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Authorised Translation from the French


[Illustration: DR. METCHNIKOFF IN HIS LABORATORY.]


LIFE OF ELIE METCHNIKOFF
1845-1916

by

OLGA METCHNIKOFF

With a Preface by Sir Ray Lankester K.C.B. F.R.S.







London
Constable and Company Ltd.
1921





PREFACE


It has been a great satisfaction to me to carry out the wish of my
dear friend Elie Metchnikoff, and arrange for the production of an
English translation of his biography. The account of his life and work
written by Olga Metchnikoff is a remarkable and beautiful record of
the development and activities of a great discoverer. It is remarkable
because it is seldom that one who undertakes such a task has had so
constant a share in, and so complete a knowledge and understanding of,
the life portrayed as in the present case: seldom that the intimate
thought and mental "adventure" of a discoverer presents so clear and
consistent a history. It is beautiful because it is put before us with
perfect candour and simplicity guided by rare intelligence and inspired
by deep affection. Madame Metchnikoff has drawn the picture of the
development of a single-minded character absolutely and tenaciously
devoted to a high purpose--the improvement of human life. It is a
story of "struggles and adventures," but they are wholly in the field
of the investigation of Nature. We read here little or nothing of the
quest for personal advancement, for fortune or official position.
These things had no attraction for Metchnikoff. He left Russia and
took an unpaid post in Paris in order to have a place to work in. He
had many devoted friends in whose company he sought refreshment and
relaxation, but all his immense energy and industry were concentrated
on the development and establishment of his great biological theory
of "Phagocytosis" and its outcome, the philosophy of life called by
him "Orthobiosis." This volume tells truly of a simple life--a life in
which the social incidents which fill so large a space in most lives
were either non-existent or unnoticed because, by the side of the great
purpose which dominated Metchnikoff's every thought and action--namely,
the advancement of Science--he was not touched by them. He was
affectionate, kind-hearted, and truly considerate of others, but was,
in a way which is traceable to his racial origin, a practical idealist
concentrating his whole strength and reason on the realisation of what
he held to be the highest good.

I had as an eager reader of memoirs on biological subjects become
acquainted with Metchnikoff's earliest publications in 1865, when
he was twenty years of age and I two years younger. I wrote short
accounts of them, as they appeared, for a chronicle of progress in the
_Quarterly Journal of Microscopical Science_, then edited by my father.
Those on a European Land Planarian, on the development of Myzostomum
(the parasite of the Feather-Star), on Apsilus, a strange new kind of
wheel-animalcule, and his protest against Rudolf Leuckart's treatment
of him in the matter of his important discoveries concerning the
Frog's lung-worm--_Ascaris nigrovenosa_--remain in my memory, and
later, in 1872, I was especially struck by his important demonstration
of the true mode of development of the gastrula of the calcareous
sponges in correction of Professor Ernst Haeckel. Many other papers
of his became known to me, until in 1881 he published his first
observations on _Intracellular Digestion in Lower Animals_, which was
the starting-point of his life's work on "Phagocytosis," to which all
his subsequent researches--during thirty-five years--were exclusively
dedicated.

In 1888 I was introduced by my friend Lauder Brunton to the great
Pasteur, and called on him at his laboratory in the rue d'Ulm. There I
met Metchnikoff, only lately arrived from Russia, and welcomed as one
of his staff by Pasteur. The next year, 1889, Pasteur was installed
in the new "Institut Pasteur" in the rue Dutot, and I met Metchnikoff
there in his new quarters. Pasteur's assistants were carrying on daily
his system of inoculation against rabies, and many British subjects
were amongst those treated. I persuaded the Lord Mayor of that year,
Sir James Whitehead, to visit the Pasteur Institute with a view to
taking steps to make some recognition of the services rendered by
Pasteur to our fellow-countrymen in treating over two hundred of them
threatened with hydrophobia. Sir James called a meeting on July 1,
1889, at the Mansion House, and placed the management of it in my
hands. As a result we obtained subscriptions to a fund which enabled
us to assist many poor British subjects to visit Paris for the purpose
of undergoing M. Pasteur's treatment, to make a donation of 30,000
francs to the Pasteur Institute, and to initiate with a sum of £300 the
formation of a fund for the purpose of establishing an Institute in
London similar in purpose and character to the Institut Pasteur. That
initial fund has step by step received generous additions and given us
the "Lister Institute" on Chelsea Embankment possessed of buildings,
site, and capital valued at more than £300,000.

After 1889 it was rare for a year to pass without my visiting Paris
both in spring and summer, and seeing a great deal of Metchnikoff
and his friends Roux, Duclaux, Laveran, and the great master of the
Pastorians, who died in 1895. Metchnikoff took me to his home and
cemented his friendship with me by bringing to me that of his gifted
and devoted wife.

Madame Metchnikoff had when a schoolgirl studied zoology under her
future husband at Odessa, and now was able to give serious help in
some of his researches. She published some experimental investigation
on the sterilisation of the alimentary canal of tadpoles and some
other researches, and having a thorough knowledge of English, which
Elie did not possess, she helped him in reading and translating from
that language. But her chief talents were in the arts of painting and
sculpture, and when they purchased their country house at Sèvres, she
built a studio in the garden in which to pursue her vocation.

Metchnikoff on several occasions came to England to take part in
"congresses" or to give special addresses, and often stayed a day or
two with me in London.[1] I was with him at the Darwin Celebration at
Cambridge in 1909, and the last occasion when he came was to give the
Priestley Lecture of the National Health Society in November 1912.
At my request he selected "The Warfare against Tuberculosis" as his
subject, and gave a most valuable account of the history and actual
condition of that enterprise, relating the important results of his
expedition to the Kalmuk Tartars for the purpose of studying the
immunity from and the liability to infection by tuberculosis among
that nomad population. The lecture was delivered in French, and I made
a translation of it which appeared with numerous illustrations in the
journal called _Bedrock_, published by Constable & Co. I mention that
publication here as it is the only one excepting the three lectures on
"The New Hygiene" (Heinemann, London, 1906) originally published in
an English form by Metchnikoff, and deserves more attention from the
English medical public than it has received.

  [1] He received an honorary degree at Cambridge in 1891, and
      also attended the International Medical Congress in London
      in that year. In 1901 he gave a lecture at Manchester on the
      intestinal flora. In 1906 he gave a course of three lectures
      in London on "The New Hygiene." I translated them for him,
      and they were published as a little volume by Heinemann.

I found Metchnikoff a delightful companion. He always had something
new or of special interest to show to me at the laboratory--some
microscopical preparation, the digestive process in Protozoa,
the microbian parasite of a water-flea, a new method of dark
ground illumination with high powers (Commandant's method for film
production), the newly discovered Treponema of syphilis, or the
experimental inoculation of a disease under study. Sometimes I
would lunch at his house, when, although he neither smoked nor took
alcoholic drinks himself, he made a point of giving me first-rate
claret and a good cigar. It was about the year 1900 that he arranged
for the preparation of a pure "sour milk" made by the use of a special
lactic ferment (selected and cultivated by himself), and this he took
regularly. I found it a most agreeable food, and for several years made
it an article of my own diet. He was very careful about the possible
contamination of uncooked food by bacteria and the eggs of parasitic
worms, and in consequence had "rolls" sent to him from the bakers each
in its separate paper bag, whilst he would never eat uncooked salads or
fruit which could not be rendered safe by "peeling." This was not an
excess of caution, but resulted from his characteristic determination
to carry out in practice the directions given by definite scientific
knowledge, and to make the attempt to lead so far as possible a life
free from disease. Often when I arrived in Paris he would invite me to
lunch at one of the leading cafés, and though he ate very simple food
himself took keen pleasure in ordering the best for me and thoroughly
enjoyed the change of scene and the amenities of a first-rate
restaurant. During one of his visits to London, I remember that he was
invited, and I with him, on two or three occasions, by leading London
physicians to dinner-parties. He was greatly shocked at the amount of
strong wine which his hosts and fellow-guests consumed, and assured me
that in Paris it would be injurious to the reputation of a physician
were he not to set an example of either abstinence or great moderation.

Metchnikoff was not only exceedingly gentle and courteous in his
treatment of servants and employés, but he and his wife contrived on
a very small income to help in a most substantial way poor neighbours
and those who had met with misfortune whether they were of French or
Russian nationality. They had many friends in the world of science and
art, real workers and thinkers, including those who had not and those
who had "arrived." With them I met and spent a long and interesting
day with Rodin the sculptor and the son of Léon Tolstoï, who was
working in a Paris studio. Among the pleasures which I have derived
from the _Life_ are the accounts of places such as Naples and Messina,
where I stayed in order to study the embryology of marine animals as
Metchnikoff did; and also the appearance in these pages from time to
time of old friends such as Nikolas Kleinenberg, whom Metchnikoff
met at Messina in 1883. I had formed an intimate acquaintance with
Kleinenberg at Jena in 1871, when he was working at his classical
monograph on Hydra, and continued it at Naples in 1875. From Messina,
where he became Professor in 1875, Kleinenberg sent me for publication
in the _Quarterly Journal of Microscopical Science_ his valuable
memoir on the embryology of a species of Earthworm, and also rare and
interesting specimens of Cephalopoda.

Another great and noteworthy figure about whom all zoologists are
glad to learn as much as possible is Kovalevsky. Metchnikoff made his
acquaintance at Naples in 1864, and they formed a close friendship
for one another. Later, in 1867, they shared the Baer Prize of the
Petersburg Academy for their discoveries in embryology (p. 58). In
1868 Metchnikoff had a dispute with Kovalevsky as to the origin of the
nervous system of Ascidia (p. 62), concerning which he subsequently
admitted that he was wrong and Kovalevsky right. There is no doubt that
Kovalevsky, by his numerous important investigations of invertebrate
embryology, and especially of that of Ascidia and Amphioxus, laid
the foundation of _cellular_ Embryology, and the modern study of the
embryology of Invertebrates. Metchnikoff's contributions were also of
great value and importance (pp. 51, 52, 53, and pp. 72 and 73), though
he has not so great a triumph in animal morphology to his credit as
Kovalevsky's discovery of the close identities of the development of
organs in Ascidia and Amphioxus. I had long cherished profound esteem
for Kovalevsky when in 1896 I met him and his daughter at Wimereux
with Professor Giard. He came in the autumn of that year to London,
but left unexpectedly owing to some nervous fear of annoyance by the
police. The great position of Kovalevsky was deliberately ignored in
a German history of Zoology,[2] published just before the Great War.
Metchnikoff describes Kovalevsky as a young man, small and timid, with
shy but cordial manners and the clear sweet eyes of a child: he had
(like Metchnikoff) for Science an absolute cult--"no sacrifice was too
great, no difficulty too repellent for his ardour."

  [2] By Prof. Hertwig of Munich.

       *       *       *       *       *

It is, I think, desirable to assure the reader of this book that the
actual state of knowledge in regard to various subjects discussed
in the _Life_ at the time when they were made the subjects of study
by Metchnikoff is fairly and correctly sketched, and the growth and
development of his views and original discoveries are correctly given.
But it must be remembered that this _Life_ is not a critical discussion
of the steps by which our knowledge of cell-layers, of intracellular
digestion, and other factors contributory to Metchnikoff's doctrine of
Phagocytosis and its outcomes were reached. Others played an important
if a subsidiary part in building up that knowledge. What we have here
is an account of the growth of Metchnikoff's own observations and
theoretical inferences, which were so independent, and founded on
such decisive original observations, as to make him a solitary figure
contending, and successfully contending, during the best years of
his lifetime for the recognition of a great generalisation for long
opposed by most of the medical and physiological authorities of the
time, and finally established by his lifelong researches and those of
his faithful pupils and coadjutors. The recognition of the validity
of _the doctrine of phagocytosis_ in relation to wounds, disease,
immunity, and normal healthy life is the triumphant result of the
scientific insight and boundless energy of Elie Metchnikoff.

                                                E. RAY LANKESTER.




                               CONTENTS


                                                                PAGE

  PREFACE                                                          v

  INTRODUCTION                                                   xxi


                               CHAPTER I

  1845. Panassovka--Metchnikoff's parents--Country life in
      Little Russia                                                1


                              CHAPTER II

  Metchnikoff's brothers and sister--Childish characteristics      8


                              CHAPTER III

  1850. Journey to Slaviansk--The coach attacked by peasants      12


                              CHAPTER IV

  1851. Departure for Kharkoff--Town life                         16


                               CHAPTER V

  1853-1856. Leo Metchnikoff's illness--Private tutors--
      Botanical studies--A memorable birthday                     19

                              CHAPTER VI

  Ancestors of the Metchnikoff family--The great "Spatar"--Leo
      Nevahovitch                                                 23

                              CHAPTER VII

  1856-1861. The Kharkoff Lycée--Bogomoloff and Socialism--
      Atheism--Natural History studies--Private lodgings--
      Private lessons in histology from Professor Tschelkoff
      --A borrowed microscope--First article--Italian opera--
      The gold medal                                              28

                             CHAPTER VIII

  An early love--A schoolfellow's sister--A pretty sister-in-law  35


                              CHAPTER IX

  1862. Journey to Germany--Leipzig, Würzburg--A hasty return     37


                               CHAPTER X

  1863. Kharkoff University--Physiology--The Vorticella--
      Controversy with Kühne--_The Origin of Species_--
      Gastrotricha--University degree                             40


                              CHAPTER XI

  1864-1866. Heligoland--Giessen Congress--Leuckart--Visit
      to Leo Metchnikoff at Geneva--Socialist gatherings--
      Metchnikoff's discovery appropriated by Leuckart--Naples
      --Kovalevsky--Comparative embryology--Embryonic layers--
      Bakounine and Setchénoff--Cholera at Naples--Göttingen--
      Anatomical studies--Munich; von Siebold--Music--Return
      to Naples--Intracellular digestion                          43


                              CHAPTER XII

  1867-1868. Petersburg--Baer Prize--Return home--Friendship
      with Cienkovsky--Odessa--Naturalists' Congress at
      Petersburg--Departure from Odessa--Zoological Lecturer's
      Chair at Petersburg--Messina--Enforced rest--Reggio--
      Naples--Controversy with Kovalevsky--Visit to the
      B. family--Mlle. Fédorovitch--Educational questions--
      Difficulties of life in Petersburg                          58


                             CHAPTER XIII

  1868-1873. Slight illness--Engagement to Mlle. Fédorovitch--
      Marriage--Illness of the bride--Pecuniary difficulties
      --Spezzia--Montreux--Work in Petersburg University--The
      Riviera--Coelomata and Acoelomata--St. Vaast--Panassovka
      --Madeira--Mertens--Teneriffe--Return to Odessa--Bad news,
      hurried journey to Madeira--Death of his wife (1872)--
      Return through Spain--Attempted suicide--Ephemeridæ         65


                              CHAPTER XIV

  1874. Anthropological expedition to the Kalmuk steppes--
      Affection of the eyes--Second expedition to the steppes--
      The eggs of the _Geophilus_                                 82


                              CHAPTER XV

  1875. Studies on childhood--The family in the upper flat--
      Lessons in zoology--Second marriage--Private life--Visit
      and death of Lvovna Nevahovna--Conjugal affection           86


                              CHAPTER XVI

  1875-1880. Metchnikoff at the age of 30--Lecturing in Odessa
      University, from 1873 to 1882--Internal difficulties--
      Assassination of the Tsar, Alexander II.--Further troubles
      in the University--Resignation--Bad health: cardiac
      symptoms--Relapsing fever--Choroiditis--Studies on
      Ephemeridæ--Further studies on intracellular digestion--
      The _Parenchymella_--Holidays in the country--Experiments
      on agricultural pests                                       96


                             CHAPTER XVII

  1881-1882. Death of his father- and mother-in-law--Management
      of country estates--Agitation and difficulties--Departure
      for Messina with young brothers- and sisters-in-law        112


                             CHAPTER XVIII

  1883. Messina--Inception of the phagocyte theory--Encouragement
      from Virchow and Kleinenberg--First paper on phagocytosis
      at a Congress at Odessa in 1883--The question of _immunity_
      --Article in Virchow's _Archiv_, 1884                      115


                              CHAPTER XIX

  1884-1885. Ill-health of his wife and sister-in-law--Journey
      to Tangiers through Spain--Villefranche--Baumgarten
      criticises the phagocyte theory                            123


                              CHAPTER XX

  1886. A Bacteriological Institute in Odessa--Unsatisfactory
     conditions--Experiments on erysipelas and on relapsing
     fever                                                       127


                             CHAPTER XXI

  1887. Hygiene Congress in Vienna--Wiesbaden--Munich--Paris
      and Pasteur--Berlin and Koch--Failure of anthrax
      vaccination of sheep--Decision to leave Russia             131


                             CHAPTER XXII

  1888. The Pasteur Institute--Dreams realised--Metchnikoff
  at 50--Growing optimism--Attenuated sensitiveness--The
  Sèvres villa (1898)--Daily routine                             135


                             CHAPTER XXIII

  1892. Opposition to the phagocyte theory--Scientific
  controversies--Experiments in support of the phagocyte
  theory--Behring and antitoxins--The London Congress--
  _Inflammation_                                                 147


                             CHAPTER XXIV

  Cholera--Experiments on himself and others--Illness of M.
  Jupille--Death of an epileptic subject--Insufficient results   154


                             CHAPTER XXV

  1894. Pfeiffer's experiments--The Buda-Pest Congress--
      Extracellular destruction of microbes--Reaction of the
      organism against toxins--Dr. Besredka's researches--
      Macrophages--The Moscow Congress--Bordet's experiments     158


                             CHAPTER XXVI

  1900. Immunity--Natural immunity--Artificial immunity          168


                            CHAPTER XXVII

  1893-1905. Private sorrows--Death of Pasteur--Ill-health
      --Senile atrophies--Premature death--Orthobiosis--
      Syphilis (1905)--Acquisition of anthropoid apes (1903)     181


                            CHAPTER XXVIII

  Researches on the intestinal flora--Sour milk                  196


                             CHAPTER XXIX

  1908. The Nobel Prize--Journey to Sweden and Russia--A day
      with Léon Tolstoï                                          199


                             CHAPTER XXX

  Intestinal flora--Infantile cholera--Typhoid fever--Articles
      on popular Science                                         206


                             CHAPTER XXXI

  1911. Expedition to the Kalmuk steppes to study tuberculosis
      --Plague                                                   210


                             CHAPTER XXXII

  Further researches on the intestinal flora--_Forty Years'
  Search for a Rational Conception of Life_                      220


                            CHAPTER XXXIII

  Unpleasant incidents--The fabrication of lacto-bacilli--St.
      Léger-en-Yvelines--Return to Paris--First cardiac attack
      --Evolution of the death instinct--Notes on his symptoms   225


                             CHAPTER XXXIV

  1914. Return to St. Léger-en-Yvelines--Norka--Studies on the
      death of the silk-worm moth--War declared--Mobilisation    237


                             CHAPTER XXXV

  1915. Return to Paris--The deserted Institute--Memoir on the
      Founders of Modern Medicine--Metchnikoff's Jubilee--Last
      holidays at Norka                                          244


                             CHAPTER XXXVI

  1916. Bronchial cold--Aggravated cardiac symptoms--Farewell
      to Sèvres--Return to the Institute--Protracted sufferings
      --Intellectual preoccupations--Observations on his own
      condition--The end--Cremation.                             254


  EPILOGUE                                                       276

  BIBLIOGRAPHICAL APPENDIX                                       285

  INDEX                                                          291




                             INTRODUCTION


On a calm summer evening we were seated together on our terrace.

On the preceding day, one who hardly knew my husband had come to ask
him for information concerning his life, with the object of writing
his biography. We were saying to each other how inevitably superficial
and incomplete such a biography was bound to be; how difficult such a
task is for a biographer, even when fully informed; how necessary it
is to be thoroughly acquainted with a man and with every phase of his
existence in order to give a truthful picture of his character and of
his life. The intimate side is bound to remain more or less closed to a
stranger; in order to decipher it, it is indispensable for the writer
of a biography to have lived in complete communion of spirit with its
subject. Our long past, spent together, fulfilled all these conditions.

My husband's whole life was well known to me. My mother-in-law had
often told me vivid stories of his childhood; he himself willingly
talked to me about his past. As to the second part of his existence, we
had lived it together.

In order clearly to understand his character, at once both complex and
one-sided, it was necessary to possess the key to his psychology. In
his life, as in his work, everything was so closely knitted that it was
impossible to understand the whole without knowledge of every link of
his evolution.

In the soothing calm of that summer evening, I submitted my reflections
to him; he warmly encouraged me, and I then and there resolved to write
his biography. He advised me to relate his whole life without any
reticence, considering that thus alone does a biography justify its
existence. That advice was to guide me, within limits, for to dissect
an individual life without touching other lives as well is not always
possible.

Numerous were the difficulties before me; yet, I considered the task as
a mission, hoping, in spite of all, that this biography would present a
true picture of the life and evolution of Elie Metchnikoff.

We talked over this project for a long time. The moon now appeared
above the trees, the soft light tracing silver designs through the ivy
leaves. The lawn, the walnut tree in front of the house, and everything
around us was bathed in peaceful radiance. Under its mysterious charm,
we ceased to speak, we listened to the inward voices of nature and of
our own hearts.

In youth, vague reveries fill our minds; after a long life, distant
memories.... He whose life I describe is no more.... Without his help
my task could not have been accomplished.

Often, when he was not too tired, he would sit comfortably in his
armchair and recount to me with his usual spirit and animation some
period or episode of his past. I read to him a sketch of the first part
of this biography and a few chapters only of the second, which was
hardly begun. Thus we spent many evenings, never to be forgotten.

He wanted this biography written, for he held that the evolution of
a mind, of a character, of a human life is always an interesting
psychological document. During his long and painful illness, he urged
me to relate the "last chapter" of his life; he hoped that his attitude
in the face of death might diminish the fear of it in others. Also
he considered that men are rare who are conscious until the end;
even rarer, those who reach the development of the "death-instinct."
Therefore, according to him, an example would be interesting.

I have tried to accomplish his desire within the measure of my strength.

The only object of this simple and truthful story is to show Elie
Metchnikoff as he was, a help, a support, and a lesson to others.

I dedicate this book to his dear memory.

                                                OLGA METCHNIKOFF.

  SÈVRES, _15th Dec. 1918_.




                               CHAPTER I

  Panassovka--Metchnikoff's parents--Country life in Little Russia.


In Little Russia, in the steppe region of the province of Kharkoff,
is situated the land of Panassovka, which belonged to the Metchnikoff
family. It is now sold, it has passed into strange hands, but it was
once the patrimony of Ilia Ivanovitch, father of Elie Metchnikoff.

The country around Panassovka is neither beautiful nor rich: steppes,
hillocks covered with low grasses and wild wormwood; a poor village,
meagre vegetation, no river; the whole impression is a melancholy one.
But what boundless space! What soft, silver grey colouring! And, in the
mornings and evenings, what fresh, cool air, and what a delicious aroma
of wormwood leaves!

The house of Panassovka, a little way from the village, is situated
on a hill which slopes gently towards a pond. It is like that of any
other middle-class landowner in Little Russia. It has only one storey
and two flights of steps on the principal façade, opening into a
deserted courtyard with no view but the high road. On the other side
a semicircular terrace, with columns and steps, leads to the garden,
composed of a few meagre flower-beds and fruit trees, reaching to the
pond. On the bank, a distillery and a very well-kept kitchen garden.

The house is arranged inside in a commonplace manner, with no claim to
beauty or comfort. The furniture, devoid of style or elegance, neither
comfortable nor fashionable, is distributed quite inartistically. On
the other hand, great care is evident in everything that pertains
to the table: the cellars and larders are full of provisions, and
obviously constitute the principal preoccupation of the masters of
the house. And indeed the hospitable table of Panassovka is renowned
throughout the neighbourhood.

According to a very fine portrait, painted in 1835, Ilia Ivanovitch was
at that time a handsome young man with regular features, tender blue
eyes, and curly fair hair. He was very intelligent, but his mind had
that sceptical turn which prevents men from taking life seriously and
which paralyses activity. Moreover, he had an Epicurean temperament and
was in the army.

He had married, when very young, Emilia Lvovna Nevahovna, sister of one
of his brother officers in the Imperial Guard, a very attractive and
unusually intelligent girl. Her beauty was of the Jewish type, with
splendid dark eyes, and she had a bright and lively disposition as well
as a kind and tender heart. Her friends called her "Milotchka," which,
in Russian, means "charming"; in her old age she loved to relate that
the great Russian poet, Pushkin, once said to her at a ball, "How well
your name suits you, Mademoiselle!"

After his marriage, Ilia Ivanovitch remained in Petersburg, leading
a merry life with his brothers-in-law, and giving no thought to the
future; it took him but a few years at that rate to spend the whole of
his wife's inheritance. And three children were growing up whose future
had to be thought of. It was then that Ilia Ivanovitch's distant
estate was remembered, away in a remote part of Little Russia. What
energy, what perseverance had to be displayed by his wife before she
could persuade him to take refuge there! and how hard it must have
seemed to the gay officer to leave the capital for the lonely and
monotonous life of the country! However, departure was decided upon.
The two boys, Ivan and Leo, were placed in a school at Petersburg, to
be prepared for the Lycée and the Law School. Ilia Ivanovitch obtained
a post as Remount Officer for two Guards regiments, and started with
his wife, his daughter, an aunt, and a younger brother, to settle down
in the country.

The family settled at first in the old Ivanovka house, where a son,
Nicholas, was born. Though they wished to have no more children,
one more child was born two years later, on the 16th May 1845--Elie
Metchnikoff.

The Ivanovka house was old and inconvenient; Ilia Ivanovitch decided
to build a new one at the other end of his estate, in a place called
Panassovka, which thus became the family home.

Emilia Lvovna threw herself into her domestic occupations with her
usual energy and ardour. She was anxious to improve the situation,
which had become precarious, and wished at the same time to create
for her husband an environment suited to his Epicurean tastes. Ilia
Ivanovitch loved cards and the table, both tastes easy to satisfy in
the country, and which became the pivot of life at Panassovka. The
great daily problem was the question of meals, and long conversations
had to take place with the cook and with the housekeeper concerning
catering.

Thanks to serfdom, servants were very numerous and everything could
be manufactured at home. The "diévitshia" (maid-servants' room) was
crowded with maids, seamstresses, needle-women, washer-women, etc.,
under the direction of a fat, middle-aged woman named Duniasha. She
wore a silk kerchief on her head, and was invariably clothed in a
white dressing jacket and a brown skirt with white spots. A regular
autocrat, she ruled her little world with a rod of iron; as soon as her
heavy, felt-slippered steps were heard, the maids whispered to each
other, "Avdotia Maximovna!" conversations ceased, and every one became
absorbed in her work.

Among the male retainers, the first place was held by Petrushka, the
valet. Careless and often drunk, he was nevertheless a good fellow; he
was usually to be found asleep behind the screen in the hall. The upper
servants, the cook, coachman, and others left their work to be done by
their underlings, the scullery boy, postilion, page-boy, etc. In fact,
everything followed the routine usual in every Russian household in the
time of serfdom.

Emilia Lvovna directed the children's education; her personal teaching
consisted chiefly in tender indulgence, but it was she who chose the
nurses and teachers. As long as the boys were small, their great-aunt
Elena Samoïlovna looked after them; afterwards they were handed over to
tutors and professors. Ilia Ivanovitch's activities consisted in buying
horses at fairs and in studs and in convoying them to Petersburg.
These journeys took a long time, by stages and relays of horses. Ilia
Ivanovitch took advantage of them to gamble heavily and to enjoy
pleasures which the country did not offer.

Agriculture was very restricted at Panassovka, for the property
consisted mostly of pasture land for horses and sheep. The younger
brother, Dmitri Ivanovitch, had undertaken the management of the
estate. He was entirely devoted to the family of his elder brother,
whom he had followed into the country. Though only a few years younger,
he used the respectful second person plural in speaking to Ilia
Ivanovitch, whilst the latter said "thou" to him. Dmitri Ivanovitch
was tall, thin, and taciturn, a silent pipe-smoker. The lively Emilia
Lvovna often said to him, "But why do you never talk, Mitienka?" To
which he invariably answered, "It is not every one who is as talkative
as you are, Emilia Lvovna." Yet they were on the best of terms. Dmitri
Ivanovitch would have gone through fire for his sister-in-law, as she
well knew. She had the utmost confidence in him, and depended upon his
support in every difficult circumstance.

At Panassovka the men spent the greater part of the day, and often even
of the night, in playing cards; games were organised between neighbours
and relations, and that occupation was considered most important. Meals
were prolonged indefinitely; everything was served in abundance and
eaten with a connoisseur's appreciation, each dish being discussed.
After the meal was over, the cook would make his daily appearance,
and the next day's _menu_ was drawn up by the whole party. After a
siesta, gambling was resumed. Thus the days went by in the cult of good
cheer and of cards, interspersed with conversations about horses and
sometimes about politics.

By this time Ilia Ivanovitch was beginning to become bald and obese.
It is difficult to define what was his inner life; not even to his
wife did he ever speak of it. As to his children, he petted them when
they were small, but as they grew up, their intercourse with him was
limited to kissing his hand morning and evening. He was not indifferent
to their welfare, but left it entirely to his wife's active solicitude.
The children were on very different terms with their mother; not
only did she spoil them, but also always eagerly shared all their
childish interests. Owing to that, and to her bright and affectionate
disposition, they looked upon her as their intimate friend and
confidante.

Masters and servants were on good terms, relations between them were
even remarkably human, according to the ideas of the time, and in spite
of certain customs inherent to serfdom. For instance, the younger maids
were punished by having their faces slapped and their hair pulled.
Even the kindly and peaceable Dmitri Ivanovitch would soundly box his
valet's ears when he found him drunk. At that time such things were not
thought cruel or humiliating, but looked upon as a paternal correction.
The peasants had confidence in their "barin" (master) and consulted him
or appealed to his generosity when in trouble.

Ilia Ivanovitch never opposed the free choice of his serfs in
matrimony, a rare tolerance at that time. According to custom every
betrothed couple came to salute him, the young man in his Sunday
clothes and a fine, bright-coloured scarf, the girl wearing an
embroidered bodice and a head-dress of many-coloured ribbons. They
knelt before him and bowed three times to the ground, then offered him
sacramental loaves, hard and shaped like pine cones, on beautifully
worked diapers. Ilia Ivanovitch and Emilia Lvovna blessed the bride and
bridegroom with "ikons," embraced them, and gave them a sum of money
for the wedding.

The Metchnikoffs were liked by their peasants and looked upon as good
masters.




                              CHAPTER II

  Metchnikoff's brothers and sister--Childish characteristics.


The two elder children, Ivan and Leo, were educated at Petersburg,
whilst Katia, the only daughter, was brought up at home. Like all
other girls of noble family, she was educated with the object of being
suitably married. She was a slender, pretty brunette, like her mother,
but less beautiful. Though sensitive and intelligent, she interested
herself in nothing but the reading of French novels. There was a great
difference in age between Katia and her little brothers, whilst there
were only two years between them. Kolia (Nicholas) was the old aunt's
favourite, a fine, handsome boy with velvety black eyes; his slow and
grave movements had earned for him the nickname of "Peaceful Papa."

The youngest of the family, Ilia (Elie), on the contrary, was full of
life and spirits. Fair and slender, with silky hair and a diaphanous,
pink and white complexion, he had small, grey-blue eyes, full of
kindliness and sparkle. Very highly strung and impressionable, his
temper was easily roused, and he was so restless that he went by the
name of "quicksilver." He always wished to see everything, to know
everything, and found his way everywhere. When, after a long silence,
there was a sudden outburst of many voices around the card-tables, he
would rush to the drawing-room, saying, "Are they going to fight?"
He ran about the house all day, following his mother as she attended
to her various duties; he examined the provisions, tasted everything,
and even went to the "diévitshia" to see what the maids were doing.
He tried to sew or to embroider, exasperated everybody, and ended by
being turned out. He would then look for something else to do, go to
see whether the table was laid, inquire about the _menu_, and ask the
queerest questions. He could only be kept quiet when his curiosity was
awakened by the observation of some natural object such as an insect or
a butterfly that he was trying to catch, or by watching the "grown-ups"
at their card games. But, of all things, music fascinated him most,
and he would remain for hours sitting by the piano listening without
a movement. He was very much spoilt by his mother, who had a weakness
for her Benjamin, and who also wished to make up for the very obvious
preference shown for Kolia by the great-aunt.

Moreover, Ilia was a frail little boy and often suffered from his eyes;
the doctor advised that he should not be allowed to cry or to rub his
eyes, and, in order to avoid this, he was permitted to have his own
way in everything. He was much too intelligent not to understand the
advantage that the situation offered and was quick to profit by it. In
the face of the least semblance of refusal or reproach, he would begin
to rub his eyes and announce in a whining tone that he was going to
cry. He was therefore very much spoilt and very capricious; his mother
said he was "neurotic"; his sister, who often had differences with him,
called him a "little beast." In reality, Ilia was very good-hearted,
tender, and loving; he was affectionate, especially with his mother,
and could always be managed by an appeal to his feelings. But if he was
sensitive to kindness, he was equally so to the least injustice. He
could not forgive his great-aunt the predilection which she exhibited
on every occasion for Kolia; for instance, at table, she would choose
tit-bits for him, and Ilia observed with bitterness that she always
reserved the chicken's breast for her favourite. Every time a chicken
was served, poor Ilia followed the dish round the table with anxious
eyes, and she invariably placed the coveted morsel in his brother's
plate.

When the day was over, Ilia was put into his little bed and told to
"say his prayers and go to sleep." But he did not obey at once: after
a thousand merry tricks, his eyelids would begin to close in spite
of him; then he would make up his mind to kneel and say his prayers,
folding his little hands: "Lord, keep and preserve father, mother,
great----" But suddenly remembering the latter's injustice towards
him, he would correct himself hastily, "No, not great-aunt, she is too
unkind!" and continue, "My sister, my brothers, everybody, and myself,
little Ilia." Still he did not go to sleep immediately; a nervous
child, he was frightened of being alone; now and then he would lift his
heavy lids to see if the maid was still there. Sometimes the latter,
thinking he had gone to sleep, would leave the room on tiptoe. Ilia,
seeing her no more, would start, raise his head and, stretching his
thin neck, send an anxious look around the room, faintly lighted by a
night-light. The vacillating flame threw trembling and dancing shadows.
Seized with intense terror, he would hide his face in his pillow and
scream with all his might. Avdotia Maximovna would then rush to soothe
him and soundly rate the servant girl, "Are you not ashamed to leave
a noble child all alone?" Ilia would then go on sobbing for a little
while, but, reassured after all, would presently sink into deep,
childish sleep.




                              CHAPTER III

  Journey to Slaviansk--The coach attacked by peasants.


In 1850 the children were taken to the baths of Slaviansk. On a warm
summer day the heavy "berlin" coach, drawn by six horses with a
postilion, rolled along the high road, across the steppes, followed at
a distance by a "tarantass."[3]

  [3] Ungainly open carriage on high wheels and without springs.

In the spacious, antique coach, with its dusty hood, sat Emilia Lvovna,
with her three children; the valet, Petrushka, dozed on the box, next
to the coachman. The tarantass was occupied by Dmitri Ivanovitch and a
cousin.

The heat was oppressive. At the start every one was excited; Emilia
Lvovna was trying to remember if anything had been forgotten and was
discussing with Katia the details of their installation at Slaviansk.
The boys hung out of the windows, gazing at the horses, at the
tarantass, and making all sorts of comments. Ilia was so restless and
talkative that he was constantly being told, "Do be quiet! Keep still!"

By degrees, however, children and "grown-ups" began to feel drowsy,
owing to the monotony of the road, the heat, and the swinging of the
carriage. The tarantass had disappeared, for Dmitri Ivanovitch wished
to visit an aunt whose house was not far from the road. The outline
of a forest was now seen on the horizon; it came nearer and nearer,
and soon the coach stopped before the forest inn. Everybody woke up,
the children were delighted to be able to run about and stretch their
limbs. They begged their mother to let them go into the forest whilst
the horses were resting, and obtained permission to go, but not too
far, and with Petrushka.

They ate an appetising lunch at the inn and the children ran off at
a gallop. Everything delighted them, the underwood, grass patches,
ravines, and mysterious paths. But they had hardly entered the forest
when they heard a sinister, confused rumour in the distance; they
stopped to listen, and recognised the voices of a tumultuous crowd. The
children's joyous excitement fell; frightened and docile, they hastened
to return to the inn, from which Emilia Lvovna, looking anxiously out
of a window, was making urgent signs to them to return. The coach was
still standing without horses, and, a little farther off, the latter
were surrounded by a crowd of peasants, of whom many were completely
drunk. They shouted vociferously, and closely pressed the coachman and
the postilion, threatening to confiscate the horses and detain the
travellers if they were not given a ransom of a thousand roubles.

Terrified, the children clung to their distracted mother; Ilia felt
her trembling, and his own little heart fluttered like a bird that
has been caught. The drunken peasants appeared to him like monstrous
ogres or brigands about to capture, perhaps kill, his family and
himself; he could hardly keep back his tears. Already the peasants
had bound the coachman and the postilion and were taking away the
horses. Clinging close to each other, the mother and children listened
anxiously; they thought again and again that they could hear the bells
of the tarantass. At last it appeared in the distance, and the children
joyously whispered, "There they are!" They hastened to inform Dmitri
Ivanovitch of what had happened. He at once went with his cousin
towards the crowd, and negotiations were opened, but for a long time
without result.

At last the cousin had a happy idea; he declared he would go back to
his aunt's house in the neighbourhood and borrow the thousand roubles
from her. The peasants consented to let him go alone, keeping the other
travellers as hostages. After a time, which to the children seemed
endless, the sound of the tarantass bells was again heard, accompanied
this time by numerous heavy footsteps, and the vehicle reappeared,
escorted by a company of soldiers commanded by two officers. Instead
of going to his aunt's, the cousin had gone to a neighbouring military
camp and was bringing assistance.

There was a sudden change of scene. Emilia Lvovna and Katia furtively
made the sign of the cross. Ilia had let go of his mother's hand and
was no longer clinging to her, but, stretching his head forward and
opening his eyes wide, eagerly waited to see what was going to happen.
"Now," he thought, "we shall not be captured; it is their turn; I am
glad!" And, perhaps for the first time in his life, his little heart
was moved by feelings of hatred.

In the meanwhile a repulsive scene was going on: a hand-to-hand
struggle, invectives and screams. The peasants were securely bound.
Men and women hastened from a neighbouring village; one of the women
slapped an officer's face. Furious, he ordered the soldiers to fill her
mouth with earth; she was thrown on the ground; the new arrivals in
their turn attacked the soldiers, and a regular battle raged.

Ilia was alarmed, shaken, and profoundly disgusted with that exhibition
of brutality. The coachman and postilion, their bonds unloosed,
hastened to put the horses in, and whilst reprisals were still going
on, the family hurried away. They reached Slaviansk without further
trouble, excitedly talking over their adventure. This episode was the
first deep and definite impression which remained on little Ilia's
mind; it struck him so much that he kept the memory of it during his
whole life.

From that moment he held crowds, violence, and all manifestations of
brute force in the utmost horror, whatever their cause might be.




                              CHAPTER IV

  Departure for Kharkoff--Town life.


The following year was to be spent at Kharkoff. Katia was now seventeen
and her marriage had to be contemplated.

The boys' life was still quite a childish one, made up chiefly of games
and mischief. Kolia had been taught to read by the great-aunt; Ilia
had learnt by himself, asking people now and then for the name of some
letter. He was able to read fluently quite early.

The departure for Kharkoff was a great event, prepared long beforehand.
The children, delighted at the prospect of a change, impatiently waited
for the moment to start. At last every one was seated in the coaches
and, saying to the coachman, "Off! God keep us," they started to drive
along the high road through the steppes.

Life at Kharkoff was very much the same as at Panassovka, with
social elements added. Moreover, the children's liberty was somewhat
restricted. Already on the journey they were given to understand that,
in a town, they could not go out alone, nor shout in the streets, nor
point at people and things with their finger, and that they should
have to make less noise, even in the house. For the first time they
unconsciously realised that their family was not the centre of the
universe, that there were many others who also had to be taken into
account. Ilia did not welcome this discovery.

The flat occupied by the Metchnikoffs was on the first floor, above
that of the owner of the house. One day when the children were
running about, making a fearful noise, some one came up to say that
the landlady was ill and begged that the noise should cease. Ilia,
interrupted in the midst of a game, became furiously angry; in his rage
he seized a whistle, and stooping to a crack in the floor, whistled
with all his might. It was only with much difficulty that he was
induced to stop and to calm himself.[4]

  [4] Metchnikoff himself insisted upon the recital of this
      episode, for which he had felt some remorse. He considered
      that, in a biography, disagreeable traits were not to be
      omitted.

The children's horizon soon widened; Dmitri Ivanovitch took them to
the theatre and a new and fantastic world opened out to them. The very
next day they attempted a performance of the play they had seen; soon,
on Kolia's suggestion, they began to compose plays for themselves.
Kolia wrote a drama entitled "Burning Tea," in which the hero having
offered his friend tea that was too hot, the latter burnt his tongue;
a duel ensued, etc., etc. Ilia hastened to follow his brother's
example. He composed something in the same style, but even more absurd.
Having realised that it was so, he gave up literature. That period
was for him a series of disappointments which perhaps helped to lead
him to the path he was ultimately to follow. His brother, following
the "grown-ups'" example, played cards with other boys or with the
maids. Ilia attempted to do the same, but his nervousness left him no
self-control; he lost continually and games generally ended in quarrels
and tears; he became disgusted with cards for the rest of his life.
Kolia was fond of muscular exercises, such as gymnastics, wrestling,
etc. Ilia, younger and therefore weaker, was constantly humiliated, and
his pride kept him away from physical amusements. Thus, by means of
elimination, he became gradually isolated from surrounding influences.
But, at that time, no new element had intervened in his daily life and
he spent his existence in the gentle warmth of his mother's tenderness,
absorbed in his childish games and studies.




                               CHAPTER V

  Leo Metchnikoff's illness--Private tutors--Botanical studies--A
  memorable birthday.


In 1851, in the middle of the winter, the Metchnikoffs heard that Leo,
their second son, was suffering from hip-disease, and the doctors
advised that he should be taken away from Petersburg. Poor Emilia
Lvovna was in great despair and shed many tears; her brother-in-law,
Dmitri Ivanovitch, calmly announced that he was going to fetch Leo. He
took his great fur coat, his fur cap and fur-lined boots, and started
that very day for Petersburg by coach. He took but the necessary time
to go and to bring Leo back, only stopping at relays to change horses.

The boy was then thirteen years old, handsome, gifted, and intelligent;
he walked with crutches, but his general health seemed good, and it was
decided that he should work at home to prepare for the Lycée, under the
tuition of students as tutors. Thus a new element was introduced into
the family life.

In 1853 Leo had as a tutor a student named Hodounof, a very intelligent
young man, who wished not merely to teach him but to impart to him
the love of science. Leo was extremely gifted and worked with great
facility, but he lacked concentration and was therefore somewhat
superficial. This cooled his tutor's enthusiasm, whilst on the other
hand he became more and more interested in little Ilia. It was in
the course of country walks that they were drawn together. Hodounof
used to take Leo for walks in order to study the local flora, and Ilia
came out with them, at first for the sake of the exercise. But soon he
became interested in the flowers and showed so much taste for botany
that he attracted Hodounof's notice; soon the tutor's interest became
concentrated on the little boy and he gave him serious attention.

It was with a real enthusiasm that Ilia gathered and studied plants;
he soon became thoroughly acquainted with the local flora. He thought
himself very learned already and wrote memoirs on botany. Passionately
fond of teaching, he used to offer all his pocket-money to his brothers
and other children to induce them to hear lectures which he gave them.
His vocation was fixed from that moment. He was then eight years old.

When the family returned to Kharkoff he spent all he had in buying
books on natural history, which he read with passionate interest. These
contained many things that he could not understand, but his curiosity
was all the greater. When he was eleven years old his passion for
natural history almost cost him his life. While fishing for hydra in
a small pond he was so eager that he fell into the water and was only
pulled out with great difficulty.

That particular day, his own and his father's name day, was nearly
fatal to him, not only through water but through fire. It was a family
custom to hold a great gathering of friends and relations at Panassovka
on St. Elias's day. Preparations for the feast began days beforehand;
the whole household was in a turmoil.

On that particular St. Elias's day, so many guests came to Panassovka
that there was not enough room in the house to accommodate them all,
and the children were transferred to a pavilion outside the house.

Whilst in the drawing-room people were talking and playing cards, the
servants were holding rejoicings of their own. Towards night-time
the majority of the coachmen and footmen brought by the guests were
completely drunk; a cigarette imprudently thrown on some hay started
a fire. Soon the stables were ablaze and many horses perished in the
flames, in spite of every effort to save them. Presently the wind
changed in the direction of the pavilion and the thatched roof caught
fire. There was a rush to save the children, who were with much
difficulty taken out through a window.

In spite of intense terror, Ilia's first thought was for his baby
nephew, the son of his sister, who had then been married a year; he ran
in affright all over the house searching for the child, and only became
calm again after he had ascertained that it had been carried out into
the garden.

Katia being married there was now no reason to spend the winter in the
town. The father and mother therefore remained at Panassovka and Dmitri
Ivanovitch took the boys to Kharkoff, where they entered the Lycée.
They had been well prepared by their tutors, and moreover spoke French
and a little German, having had special teachers for these languages.
Their French tutor, M. Garnier, was gay, boastful, and pretentious;
his idea of teaching them French literature was to memorise Béranger's
_chansons_. He was passionately fond of shooting and gave to that
sport as much time as he could, greatly to the detriment of his pupils'
studies, for they were not allowed to accompany him for fear of an
accident. Their mother, perhaps on account of her weak heart, was so
nervous that they were discouraged from any sporting tastes. The German
tutor also neglected the children: his favourite occupation consisted
in drinking beer. On one occasion he gave so much to little Ilia that
the boy conceived a lifelong distaste for beer. Ilia took advantage
of his tutors' indifference to devote himself to his favourite study
of natural history. His vocation was so obvious that it could not be
mistaken. It seems a strange thing that a passion for science should
have developed in so inappropriate an environment. Evidently the first
impulse was given by Hodounof, but, if his influence stimulated this
passion, it cannot have created it. This vocation probably had a deeper
source, and in order to discover it we should perhaps look back into
the antecedents of the Metchnikoff family.




                              CHAPTER VI

  Ancestors of the Metchnikoff family--The Great Spatar--Leo
  Nevahovitch.


The Metchnikoff family made no show of family pride; one old aunt,
however, was extremely proud of one of their ancestors, the Great
"Spatar" (sword-bearer). The following is the account given of this
ancestor by E. Picot, after a Moldavian chronicle.[5]

  [5] _Chronicle of John Neculua._

  Few men led such an adventurous life or made themselves glorious
  through such varied gifts as did Nicholas Spatar Milescu.

  His name is connected with the history of Moldavian, Greek, Russian,
  and Chinese literature. His origin, his talents, his crime, the
  mutilation he suffered, his audacious journey across the whole of
  Asia to reach Pekin, the valuable information which he gathered
  during his embassy at the Court of the "Son of Heaven," everything
  conspires to excite curiosity concerning him.

Spatar was born in Moldavia in 1625. While yet very young he went
to Constantinople, where he studied theology, philosophy, history
ancient and modern, Greek, Latin, Slavonic and Turkish. He afterwards
went to Italy to study natural science and mathematics. On his return
to Moldavia he soon became known for his erudition, acquired great
influence, and became much appreciated at Court. Owing to clever
political intrigues he preserved the simultaneous favour of several
enemy princes, one of whom, Stepanita, covered him with benefits and
honours. Nevertheless, Spatar wrote to Constantine Bassarab, in Poland,
advising him to come and to overthrow Stepanita's throne. He sent
his letter inside a hollow cane; Constantine, however, did not wish
to launch himself into such an adventure, and indignantly sent the
hollow cane and the letter to Stepanita himself. At first the prince,
naturally angry, thought of having Spatar executed; he spared his life
for the sake of his talents, but condemned him to have the tip of his
nose cut off. Spatar went to Germany, where, says the naïve chronicler,
a doctor made his nose grow again. He came back to Moldavia for a short
time and then went to Russia. Thanks to his knowledge of languages, he
was made an interpreter at the Court of the Tsar Alexis Michailovitch,
and was the first tutor of his son Peter the Great, whom he taught to
read and to write.

In 1674 the Tsar Alexis Michailovitch entrusted Spatar with a mission
in China, where he was to open negotiations with a view to commercial
and political relations between Russia and China. In the course of his
journey Spatar carefully collected all possible information concerning
the countries he traversed. He thus gathered much interesting
geographical knowledge and highly important data concerning the
commercial value of Asiatic rivers, and specially the Amour river.

At Pekin, Spatar rapidly learnt the Chinese language, occupied for
three years the post of ambassador in China, and returned to Russia
bringing back most valuable information and many rich presents given
him by the Emperor of China.

All this had excited the jealousy of the Muscovite courtiers; they
took advantage of the coincidence between the death of the Tsar and
Spatar's return to deprive him of his treasures and to have him exiled
to Siberia. But, when Peter the Great ascended the throne, Spatar
succeeded in making a letter reach him relating his misfortunes,
and the Tsar recalled him, gave him back his property, and showered
honours upon him. Spatar again became interpreter of the Embassy; Peter
consulted him in all Far-Eastern questions, and gave him confidential
documents to translate into foreign languages.

Spatar's literary activity was vast and varied. He translated the Bible
from the Greek into Roumanian; he wrote a chronicle on the origin of
Roumania, articles on theology, a Greco-Latin-Russian dictionary, and a
work entitled _Arithmetic_, in which he discussed, by means of numbers
and figures, questions of Theology, Philosophy, and Ethics. He dealt in
his writings with Art, Archæology, and History; described his Siberian
travels, China and the Amour river, and made numerous translations of
diplomatic documents. His erudition was such that his contemporaries
appealed to his knowledge as they would have consulted an encyclopædia.

He had married a Muscovite and had several sons and grandsons. Three
of his nephews came from Moldavia to join him and entered the Russian
army. He died in 1714 at the age of 80. Such is the history of the
"Great Spatar."

The following notice is to be found in Brockhaus and Effrone's
_Encyclopædia_: "The Metchnikoffs are a noble family, descended from a
Moldavian Boyar, the Spatar (sword-bearer) Joury Stepanovitch,[6] who
came to Russia with Prince Cantemir. Peter the Great gave this Boyar
large land estates. His son took the name of Metchnikoff (Russian
translation of Sword-bearer)."

  [6] This Boyar was no doubt a nephew of the Great Spatar.

The following generations included military men chiefly, one sailor,
one mining engineer, one senator, but no scientific men.

On the mother's side, Elie Metchnikoff had no ancestor as remarkable or
as romantic as the great Spatar. Yet his grandfather, Leo Nevahovitch,
was a very intelligent and highly cultivated man. He had been
Farmer-General for tobacco in Poland. A Jew by race, he took to heart
the persecutions directed against his co-religionists and defended
them in literary newspaper articles. Nevertheless he accepted indirect
advice from Alexander I. and let himself be baptized. He adopted the
Lutheran religion and his children were brought up in it.

At the beginning of the Polish Revolution in 1830, Nevahovitch was
warned that his house was about to be sacked; the warning reached him
as he was peacefully enjoying a theatrical performance. He hurried to
prepare for departure and left Warsaw with his family for Petersburg,
where he lived on his income. Having given up business, he took up
literary work and translated German philosophical works, made friends
in the literary world, and knew Pushkin and Kriloff. His children,
Emilia Lvovna amongst others, inherited his intellectual gifts. One
of his sons was a remarkable caricaturist and edited a caricature
newspaper which was very well known at the time. The Nevahovitch family
produced no men of science. Metchnikoff himself considered that he had
inherited his mother's disposition and turn of mind. In any case, his
ancestors on both sides included talented individuals, from whom he may
have inherited his gifts and his innate taste for science.




                              CHAPTER VII

  The Kharkoff Lycée--Bogomoloff and Socialism--Atheism--Natural
  History studies--Private lodgings--Private lessons in histology
  from Professor Tschelkoff--A borrowed microscope--First article
  --Italian Opera--The gold medal.


In 1856 Dmitri Ivanovitch took the boys to Kharkoff in order to make
them enter the Lycée. They passed their entrance examination quite
satisfactorily; Kolia was admitted into the fifth class and Ilia into
the one below it. They were day boarders and lived in the house of one
of their former tutors.

This was at a time when the new and liberal reign of Alexander II. was
giving birth to many hopes; the Lycées preserved but insignificant
traces of the hard regime of Nicholas I. Previous narrow and doctrinal
teaching was giving way to a current of realistic and rational ideas,
physical and natural science had become the vogue, and professors were
trying to come into touch with their pupils and to influence their
intellectual development. The boys on their side were founding mutual
instruction clubs, attending popular Sunday lectures, interesting
themselves in social questions--in fact the revolutionary movement was
beginning to strike root. Life in general was intense, aspirations
exalted, and hopes radiant.

During his first school year Elie worked assiduously in all branches of
the curriculum, and his name soon appeared on the honours list. The
Russian language teacher became his friend, and greatly contributed to
his development by choosing for him books of general knowledge. Under
this direction Elie read, among other things, Buckle's _History of
Civilisation_, which had at that time a very great influence on the
young Russian mind. According to the author's principal thesis, the
progress of humanity depended chiefly upon that of positive science;
this idea sunk deeply into the boy's mind and confirmed his scientific
aspirations.

When he reached the fifth class he formed a friendship with one of
his school-fellows, Bogomoloff, who had great influence over Elie's
ulterior development; he was the son of a colour manufacturer, and his
elder brothers were studying chemistry at the Kharkoff University with
a view to applying it to their industry. They had travelled abroad
and had brought back novel ideas and books forbidden by the Russian
censorship; they influenced their young brother, who in his turn
initiated Elie. It was thus that the latter became acquainted with
materialistic ideas and social theories; he read the _Popular Star_,
the _Bell of Herzin_, and other publications prohibited in Russia.
Little by little he lost the faith which he had held when under his
mother's influence. Atheism, however, was to him more interesting than
disappointing; it incited in him a state of general criticism. Ardently
passionate in this as in all things, he preached atheism to others
and received the nickname of "God is not." The course of teaching
at the Lycée did not escape his criticism; when he had reached the
fourth class he omitted those exercises which seemed to him devoid of
interest. On the other hand, he plunged with passion into the study of
natural science, botany, and geology.

He had ceased to be a model student, but his scientific aspirations
became stronger from day to day.

In order to cultivate foreign languages, the two brothers had been
placed in a boarding-house where morals were strict and patriarchal,
the food bad, and the director's sermons long and tedious. None of
these things suited Elie. This regime, with the addition of dancing
lessons, inspired him with the deepest aversion; he resolved to obtain
from his parents permission to take furnished rooms for himself and his
brother.

In spite of the current of political exaltation which was then
universal in Russia, Elie was too deeply immersed in his studies to
be carried away in that direction. He did at one time attend popular
lectures and the political gatherings of the students, but he felt
that science was his real vocation. He was so early and so completely
absorbed by it that he was not interested in the great movement for the
emancipation of the serfs. It is true that, at Panassovka, the question
was not acute as elsewhere, the serfs being quite happy; however,
the fact remains that it was his passion for science which kept him,
in spite of his exalted ideas and ardent soul, apart from the noble
movement for liberation.

In the third class he made friends with a group of students who were
devoted to science and to intellectual culture. Elie, owing to his
ardour and vivacity, played the part of a ferment in that little
circle, each member of which was to make a special study of certain
scientific branches in order that they might together edit a new
encyclopædia of human knowledge. He studied German so as to read in the
original the classical materialistic writers, Vogt, Feuerbach, Buchner,
Moleschott, etc. The Lycée lectures were relegated to the background.
Nevertheless, owing to his great facility of assimilation, he was
successful in every branch. Plans for his ulterior activities were soon
definitely fixed.

At that time of intense intellectual effervescence in Russia, libraries
were invaded by a number of translations of works on natural science.
Elie absorbed them with avidity, and read amongst others a Russian
translation of Bronn's book on the _Classes and Orders of the Animal
Kingdom_. He saw for the first time in the plates of that work pictures
of micro-organisms, amoebæ, Infusoria, Rhizopoda, etc. That world of
lower beings impressed him so strongly that he resolved from that
moment to devote himself to the study of them, that is, to the study of
the primitive manifestations of life in its simplest forms.

He was then fifteen years old. The two brothers now obtained from
their parents permission to live in furnished rooms, an independent
arrangement which allowed each of them to satisfy his individual
tastes. Apart from the Lycée, Kolia spent his time in playing cards and
billiards and in other amusements, whilst Elie worked with ardour, his
only recreations being music and debates on abstract subjects. When he
entered the second class he had become completely specialised. In order
to tackle serious scientific studies, he tried to come into touch with
one of the University professors. The University of Kharkoff was still
making use of ancient methods; teaching was given by means of manuals,
with practical application; but Elie, who did not know that, dreamt of
finding in laboratories assistance and means of, at least, undertaking
personal scientific work. He attended a lecture on comparative anatomy,
and, in order not to appear too young, he wore his ordinary clothes
instead of the Lycée uniform. After the lecture was over, he shyly
approached the professor and begged to be allowed to study protoplasm
under his direction. The professor received him coldly, and told him in
a pedantic tone that he was in too much of a hurry, and that he should
first of all finish his course at the Lycée and then get admitted into
the University.

It was a disappointment for the eager boy; however, he did not lose
heart but continued to attend divers University lectures, clinging
to the hope that another professor might be more sympathetic. He was
pleased with the lectures of a young physiologist, Tschelkoff by name,
and decided to make another attempt. This time he was successful. The
professor received him kindly and consented to give him private lessons
in histology. Then, fired with a passionate desire to produce something
personal in medical science, and attracted by Virchow's cellular
theory, he dreamt that he might create a general theory of his own in
medicine. In order to increase his scientific knowledge, he undertook
with his friend Zalensky the translation of Grove's work, _The Unity
of Physical Forces_. The professor of chemistry and natural history
willingly encouraged the two boys in this work, to which they gave up
the whole of the school year. Elie wasted no opportunity of learning;
during those lectures which did not interest him he used to read
scientific books. One day that he was doing so during catechism he did
not notice that the priest, wishing to know what he was reading, had
come up to him. The latter, however, was greatly impressed by the title
of Radlkoffer's learned work on _The Crystals of Proteic Substances_;
he returned the book without a word and never interfered with him again.

Through the assistance of some medical students, Elie obtained the loan
of a microscope; he studied Infusoria and imagined that he had made
divers discoveries; he hastened to write an article, and sent it to the
only scientific Russian paper then in existence, the _Bulletin of the
Moscow Society of Naturalists_. To his great joy his MS. was accepted,
but before long the young scientist perceived that his deductions
were erroneous, for he had mistaken phenomena of degenerescence for
phenomena of development. He was able to stop the publication of this
article, the first he ever wrote, and it never appeared.

Thanks to Tschelkoff, who lent him a microscope for the duration of the
holidays, he was able to study the local fauna of inferior animals. At
the beginning of his last year at the Lycée, he read a text-book of
geology by a Kharkoff professor and, with juvenile assurance, wrote a
critical analysis of it. Inserted in the _Journal de Moscou_, this was
Elie's first publication; he was then sixteen years old. Encouraged
by this success, he sent several other criticisms, but they were not
accepted.

The last examinations were coming near: Elie wished to obtain the gold
medal, not only out of pride, but in order to prove to his parents that
he deserved their assistance in order to go abroad to continue his
studies. He therefore provisionally suspended his favourite pursuits
and resumed the study of the long-neglected school programme. The last
examinations took place in the spring of 1862. It happened to be the
Italian Opera season and Elie could not resist the temptations offered
him by music. In order to make up the time, he often had to work the
whole night long at the cost of severe fatigue.

In spite of this complication, he passed his examinations brilliantly
and obtained the gold medal. He now wished for nothing but to devote
himself to scientific study.




                             CHAPTER VIII

  An early love--A schoolfellow's sister--A pretty sister-in-law.


In spite of his precocious vocation, Elie was in no wise indifferent
to his surroundings. His mind was sensitive and impressionable and his
affections deep and tender, especially where his mother was concerned.
He never undertook anything without consulting her, a sweet habit which
he preserved even in his maturity.

It was already at the age of six that he received his first love
impression: a lady came on a visit to Panassovka with her little girl
of eight, a lovely curly-headed child, sweet and graceful, a living
floweret. Ilia could not admire her enough, and was most lavish in his
attentions, offering her flowers and fruit, inventing games to amuse
her and trying by every means to make himself agreeable to her. The
presence of this charming little girl caused him great joy and tender
emotion; he wished that she might never go away.... But the visit soon
ended, and this first idyll was short-lived; new impressions were not
long in replacing it. Nevertheless the picture of the pretty child was
so deeply impressed in his mind that he never forgot her.

The second time he fell in love was when he was already at the Lycée;
one of his schoolfellows had a very pretty sister whom Elie used to
meet on half-holidays. He admired her from afar, and tried to contrive
opportunities of meeting her; she was the object of his dreams for the
whole of one term.

But he was presently to be seized by a more serious feeling. When he
was in the third class at the Lycée he came as usual to Panassovka
for the summer holidays and found there a new inmate, his elder
brother's young wife. Soon, to his own astonishment, he found that the
image of his last winter's passion was being effaced by that of his
sister-in-law. She, a pretty, fashionable girl, was bored with country
life; she criticised the simple habits at Panassovka which formed a
sharp contrast with her tastes; she soon became very unpopular and,
feeling lonely and bored, tried to attract her young brother-in-law.
Elie, at first a willing comrade, soon found himself harbouring a more
tender feeling for his sister-in-law; she complained to him of the
family's hostility, declared herself misunderstood, and easily excited
the pity and sympathy of the sensitive boy. He became her ardent
defender and went so far as to fight her battles, even with his mother,
whom he reproached with fancied injustice. For nearly four years he
remained under his sister-in-law's sentimental influence. He afterwards
freed himself completely from it, but the fact remains that she was the
first woman who inspired real sentiment in his youthful manhood.




                              CHAPTER IX

  Journey to Germany--Leipzig--Würzburg--A hasty return.


During his later years at the Lycée, Elie had attended several courses
at the Kharkoff University and had realised the inadequacy of the
teaching and the impossibility of any personal research work in the
laboratories. His greatest desire, therefore, was to go abroad to
study. At that time, the German universities, being nearer, chiefly
attracted Russian students. Their laboratories were widely opened to
foreigners, and lectures were being given by a pleiad of celebrated
professors.

In order to attain his object, Elie took care to secure his mother's
support. It was not very difficult, for she believed in her son's
scientific future and was anxious to help him; she succeeded in
convincing his father and, by means of serious sacrifices, the
necessary sum was procured. Elie, who was especially interested in
the study of protoplasm, chose the University of Würzburg, where the
celebrated zoologist Kölliker was lecturing. Thinking that in Germany
the term began in September, as in Russia, he hastened to depart. The
journey at that time was long and complicated; yet, in spite of much
fatigue, Elie only stopped one day in Berlin and hurried to Leipzig,
the centre of the book trade, in order to procure the necessary books.
He reached Leipzig in the evening and was greatly embarrassed, not
knowing where to find a lodging. A young German in the station offered
him a room in his own family's house and took him there. The next
morning, very early, Elie ran out to buy his books and, in his haste,
forgot to note the number of the house and the name of the street; it
was with the utmost difficulty that he found the place again. Much
disturbed by this misadventure, he hastened to start for Würzburg and,
on arriving there, met with a great disappointment; all the professors
were absent, this being the middle of the holidays, and the lectures
were not to begin for six weeks. The poor boy, thus alone for the first
time among strangers, felt completely lost. He was given the address of
some Russian students and he hastily sought them out, full of joy and
hope, only to be received coldly and distrustfully by his compatriots.
After this discouraging reception, he sadly proceeded to look for a
room, and having found one in the house of a disagreeable old couple,
he brought his bag there. But, as he began to unpack it, he was seized
with a feeling of such utter despair that he hastily put his luggage
together again and announced to his elderly hosts that he was going.
Surprised and indignant, they abused him so brutally that his distress
only increased; he rushed to the station, took the first train, and
returned to Panassovka without a stop. This hurried return disconcerted
his family, but, seeing the state he was in, nobody reproached him. His
mother had felt much anxiety on his account, and was in fact not sorry
to keep him a little longer under her wing. Thus, in dismal failure,
ended that first journey abroad, so ardently desired. The result might
have been very different if Elie had reached Würzburg at the right
moment, or if the Russian students had been more friendly. Too young
and too impressionable to bear absolute solitude, he could only have
been saved by his favourite studies or by a friendly environment.
His plans and fair dreams had been overthrown by a series of simple
mishaps.




                               CHAPTER X

  Kharkoff University--Physiology--The Vorticella--Controversy with
  Kühne--_The Origin of Species_--The Gastrotricha--University degree.


There was now no choice and he had to resign himself to the Kharkoff
University. There is not much to relate about this period, which was
but a fugitive episode in the course of Elie Metchnikoff, for the "Alma
Mater" did not have upon him either the influence or the prestige which
it generally exerts upon youth.

Whilst the stream of new ideas had already reached the Lycée, the
University of Kharkoff had remained extremely conservative; this was
owing to the fact that the Lycée professors were young men, whilst
those of the University were elderly and old-fashioned. Officials
rather than scientists, they were content with ancient methods, and
lectured without practical work, from obsolete and ill-chosen manuals.
A few of them drank, others neglected their work. In the Medical and
Natural Science Faculties, only two _agrégés_ were newly appointed,
Tschelkoff, the physiologist we have already mentioned, and a chemist
named Békétoff. These two were indeed scientists and master-minds, and
it was only under their direction that any one did any serious work;
the other lectures were pure formalities. Elie wished to go in for
medical studies but his mother dissuaded him. "You are too sensitive,"
she said, "you could not bear the constant sight of human suffering."
At the same time, Tschelkoff suggested the Natural Science Faculty as
being more appropriate to purely scientific activity. Elie accepted his
opinion and began to study physiology under his direction. His great
desire was to embark at once on personal research, and his teacher
advised him to study the mobile stalk of a ciliated Infusorian, the
Vorticella. The question was to determine whether this stalk presented
any analogy with muscular tissue and whether it offered the same
reactions. Elie set to work with ardour and found that the stalk of
the Vorticella had no muscular character. His memoir on the subject
appeared in 1863 in _Müller's Archives_. It provoked a severe, even
brutal, answer from the celebrated physiologist Kühne which deeply
grieved the young scientist and, stimulating his energy still further,
incited him to repeat his experiments. He obtained the same results as
the first time, and answered Kühne in a somewhat bitter manner, the
latter's tone having stirred his combativity.

Meanwhile, Elie was yearning for independent and more general study.
During his unsuccessful journey, he had acquired in Leipzig many
recently published scientific books, and, among them, Darwin's _Origin
of Species_. The theory of evolution deeply struck the boy's mind and
his thoughts immediately turned in that direction. He said to himself
that isolated forms which had found no place in definite animal or
vegetable orders might perhaps serve as a bond between those orders
and elucidate their genetic relationships. This leading idea made him
choose for his researches some very singular fresh-water creatures,
partly like Rotifera and partly like certain worms of the Nematode
group. He succeeded in establishing a new intermediate order which he
named "Gastrotricha," and which was straightway accepted.

The whole of his first year at the University was given up to those
special studies. As he was fully aware that the teaching of the
University did not answer to his aspirations, he resolved to remain
there as short a time as possible, and to get through the course of
studies in two years instead of the four which were usual. In order
to succeed in doing so, he provisionally gave up his scientific
researches, attended the lectures as a free auditor, and spent the
whole of the second year in cramming for the "candidate" examination,
which answers to a Licentiate in Western universities. It happened
again this time that the examinations coincided with the Opera season,
but, though he indulged in his passion for music, he succeeded, by dint
of a supreme effort, in passing them very brilliantly.

Having gone through the University at such an accelerated pace,
he did not come into contact with other students, who, themselves
chiefly preoccupied with politics, took little interest in a youth so
exclusively absorbed in science. He therefore formed none of those
attractive juvenile friendships which he had enjoyed at the Lycée.
His hasty University studies necessarily left lacunæ in his general
knowledge, a fact which he afterwards keenly deplored.

With the exception of Tschelkoff, his teachers had had no decisive
influence on his career, and his two years at the University formed but
a colourless episode in his life.




                              CHAPTER XI

  Heligoland--Giessen Congress--Leuckart--Visit to Leo Metchnikoff
  at Geneva--Socialist gatherings--Metchnikoff's discovery
  appropriated by Leuckart--Naples--Kovalevsky--Comparative
  embryology--Embryonic layers--Bakounine and Setchénoff--
  Cholera at Naples--Göttingen--Anatomical studies--Munich;
  von Siebold--Music--Return to Naples--Intracellular digestion.


Elie still had his Licentiate thesis to prepare. In order to do so, he
decided to spend two months in the island of Heligoland, of which the
flora and fauna were very attractive to naturalists. In spite of his
previous failure, his parents made no objection to his departure; they
gave him the little money they could spare and Elie started, in 1864.

As soon as he arrived in Heligoland he became absorbed in his work.
He proceeded with his idea of bringing light upon the genealogy
of organisms through the study of isolated forms outside definite
groups.[7]

  [7] He made researches on a very singular annulate worm, the
      _Fabricia_.

His ardour in his work attracted the attention of several German
scientists, one of whom introduced him to the celebrated botanist
Cohn, who soon became interested in him. During the walks which they
took together, they held scientific conversations full of interest for
the youth. Cohn advised him to work under the celebrated zoologist
Leuckart. Elie received this counsel with enthusiasm, but there was
a great difficulty, which was the lack of money to prolong his stay
abroad. He did not wish to ask for more from his parents and decided on
the following plan, which he expounded in the following letter to his
mother, the constant confidante of all his aspirations:

                                     HELIGOLAND, _Aug. 12, 1864_.

  DEAR MAMMA, ... I am thinking of staying here another month, after
  which I shall go (at least that is my desire) for ten days to
  Giessen, where there will be a General Congress of naturalists and
  physicians from the whole of Europe. This Congress tempts me so much
  that I want to do my utmost to attend it.

  Besides all the scientific benefit that I shall reap from
  conversations with scientists, I can also study Professor Leuckart's
  rich collections. This would complete the studies which I am
  successfully pursuing at the seaside.

  In order to realise my ardent wish to profit by such treasures, I
  must remain three weeks longer at Heligoland, travel to Giessen and
  live there for ten days; all that out of the money which was to keep
  me here until the 26 Aug. only.... Therefore, instead of living in
  the hotel, I have taken a room at a fisherman's, for half the price;
  instead of a dinner and coffee I eat what I can get and I only spend
  90 centimes a day for my food. (Food is dear, as all the provisions
  come from Hamburg and from England.) Instead of changing my linen two
  or three times a week, I only do so once or twice, which allows me to
  spend less on laundry.

  The money thus economised, together with the sum which I had put
  aside for my first installation at Petersburg, constitutes a
  sufficient capital to provide the following joys and advantages: 1°,
  I shall stay three weeks longer at the seaside, which will allow me
  to get on with my researches and to increase my collections; 2°, I
  shall attend the Congress; 3°, I shall be able to study Leuckart's
  collections and take advantage of his books and counsel.

  I beseech you not to look upon this description of my present life as
  a complaint or a murmur; on the contrary I am delighted to procure
  so many advantages at so small a cost; I am happy, too, to be able
  to assure you in all conscience that I am not wasting the money that
  you have found for me with so much care and affection. I only wish I
  could find myself oftener in the same conditions.

  Please also believe that my health is in no way suffering from my
  work. I give you my word that until now I have not had a single
  headache.

  Moreover, I do not think work is at all detrimental to health; I see
  here several German scientists who could fell an ox with their fist!
  Altogether I beseech you not to be anxious on my account; you have
  quite enough painful preoccupations without that, and I am in such
  excellent circumstances that there really is nothing to worry about.
  I kiss your hands many times.

                             Yours affectionately,

                                          ELIE METCHNIKOFF.

  _P.S._--Write to me oftener. Every word from you is so precious to me!

He did not tell his mother that he never had enough to eat. Neither did
he wish Cohn and his other acquaintances at Heligoland to notice it,
and he carefully concealed his style of living.

He went to Giessen for the opening of the Naturalists' Congress and
read with success two papers dealing with his researches at Heligoland.
Engelmann (who was to become well known as a physiologist) and he
were the youngest members of the Congress, and their extreme youth
attracted general attention. Elie at last made Leuckart's acquaintance;
he was charmed by him and definitely decided to begin at once to work
under his direction, and, as his stay abroad had thus to be prolonged,
he asked and obtained a _bursa_ from the Russian Ministry of Public
Education.

The results of his researches at Heligoland had led him to suppose
that the Nematodes (of the worm type) formed an independent group; he
now proposed to settle that question. Leuckart allowed him to work in
his laboratory during his absence for the holidays; Elie immediately
set to work and discovered a very curious and quite novel case of
alternation of generations; hermaphrodite and parasitic Nematodes
giving birth to a free bisexual generation.

Delighted with his discovery, he hastened to communicate it to
Leuckart, who was incredulous at first but had to give way to evidence
when Elie showed him all the intermediary stages. Still the German
scientist was obviously annoyed that this discovery should have been
made in his absence and independently from him. He proposed to the
young man that they should continue researches in collaboration and
publish a joint memoir. Elie accepted joyfully. In his ardour he worked
too much, and fatigued his eyesight so that he was forced to limit his
microscopical researches to a few hours a day, and Leuckart advised him
to take a rest.

It happened that Elie's brother Leo had just settled in Geneva and
invited him to stay with him; Elie started to join him. The brothers
had not met for a long time. Leo had been travelling and had resided
in many different places. He was an extraordinarily gifted man,
impulsive, brilliant, and artistic, but restless and incapable of
adhering to a steady course of action; he scattered his activities and
did not therefore produce all that his rich nature was capable of.
He had a remarkable gift for languages; he knew not only a number of
European languages but also several Oriental languages, having been
in the East, where he had occupied a post of agent in navigation and
commerce. He afterwards lived in Italy, took an active part in the
Garibaldi movement and was wounded. A clever painter, he also had real
literary talent; handsome, witty, agreeable, he was a most attractive
personality. Elie had great affection for him.

He found him surrounded with young men and studying a map. They were
discussing the acquisition of a piece of ground in Italy in order to
found a socialistic community, and Leo, who knew the country, was
to choose the locality. Elie was at once made acquainted with the
political questions of the day; the young scientist was unfavourably
impressed, for the whole reduced itself to party questions and dogmatic
discussions founded on hollow grounds. Accustomed as he already was to
positive scientific methods, vague and arbitrary theories could not
satisfy him.

On the other hand, he was deeply impressed by the personality of the
celebrated socialistic Russian writer, Herzen, who resided in Geneva at
that time. The young revolutionaries considered him as too literary and
too much of a theoretician; they themselves yearned for a direct-action
policy. Leo Metchnikoff, however, admired him fervently. Meetings
often took place in Herzen's rooms; he used to read to his guests with
wonderful effect his yet unpublished manuscript _Passé et pensées_.
A great and powerful figure, the superiority of his intelligence was
almost crushing, while his sparkling wit and the nobility of his whole
being endowed him with an incomparable and irresistible personal charm.
Metchnikoff often said that no man had left a deeper impression on his
life. As a politician, however, he had not the same prestige in his
sight.

This sojourn in a revolutionary centre interested him much, but had
the result of confirming his conviction that science was immeasurably
superior to politics, and he congratulated himself on the path he
had chosen. After he had rested, he started to return to Giessen and
stopped at Heidelberg, a centre for Russian students who gathered
around Helmholtz, Virchow, and Bunsen. He hurried to the library
in order to see scientific periodicals; one of the first that came
under his eyes was a number of the _Göttingen News_, containing a
memoir by Leuckart on the Nematodes which they had studied together;
Leuckart described, in his own name, their common researches and also
those personal to the young man, whom he only mentioned incidentally.
Elie was shocked and indignant. On his return to Giessen he tried to
obtain an explanation from Leuckart but in vain; the latter eluded his
questions and gave him no answer.[8]

  [8] All this episode was described by Metchnikoff in 1866 in
      a separate publication with great restraint and in a very
      moderate tone.

In his despair, the youth confided in Claus, a professor of zoology
whose acquaintance he had made at the Congress, who told him that
Leuckart was in the habit of such dealings, and urged Elie, as an
independent stranger, to reveal the fact. He pressed this with so much
insistence that Elie ended in following his advice; he sent an article
stating the case to Dubois-Reymond's journal. He then departed from
Giessen without taking leave of Leuckart.

Having had a _bursa_ of 1600 roubles a year granted him for two years
by the Russian Ministry of Public Instruction, he was able to undertake
a journey to the shores of the Mediterranean in order to pursue his
researches.

He had heard of a very talented young zoologist, Alexander Kovalevsky,
who also knew him by hearsay and had written him a letter full of
enthusiasm concerning the rich Mediterranean fauna and the facilities
for work in Italy. He therefore went to Naples on leaving Giessen.
Though the journey in itself had but a secondary attraction for him, he
had expected to receive a strong impression; but his imagination had
painted such grandiose pictures of the country that he had to cross,
that the reality disappointed him, and Italy, like Switzerland on a
former occasion, fell very far short of his expectations. He stopped
at Florence, which made but a poor impression on him. Museums fatigued
him, for he saw a great deal too many works of art all at once without
any previous preparation. Architecture and the plastic arts in general
did not take any hold of him. During his rapid journey he only saw the
country quite superficially and had no time to become impregnated with
its beauty. He therefore hastened towards Naples, where his work and
Kovalevsky attracted him far more.

He found in Kovalevsky a young man with shy but cordial manners and
the clear sweet eyes of a pure child, obviously an idealist. He had
for science an absolute cult, the sacred fire of the worshipper; no
sacrifice was too great, no difficulty too repellent for his ardour.
On a closer acquaintance, the small, timid young man proved to be a
hard fighter where science was concerned. The two young men formed
an excellent impression of each other, and a friendship was started
between them which was to last a lifetime. Though very different
from each other, they met on common ground, a passion for science.
They worked with the greatest energy, going together on zoological
excursions, exchanging their ideas, discussing their aspirations; a
similarity of tastes lent great attraction to their friendship.

At Giessen, Elie had read Fritz Müller's _For Darwin_, a book which
had a decisive influence on the future direction of his researches.
Fritz Müller, in his embryological works on certain crustaceans, had
been the first to confirm in a concrete manner Darwin's evolutionist
theories; he had thus demonstrated that it was chiefly in embryology
that precious indications were to be found concerning the genealogy of
organisms.[9] Under the influence of this work, Elie, who until now had
limited himself to introductory researches, resolved to concentrate
all his efforts on the comparative embryology of animals. He started
to work in that direction, and his researches confirmed him more and
more in the opinion that the key of animal evolution and genealogy was
to be sought for in the most primitive stages, in those simple phases
of development where no secondary element has yet been introduced from
external conditions. In those primordial stages, essential characters,
common to all, reveal the analogy and connections between animals from
different groups.

  [9] In later years Metchnikoff often dwelt on the fact that Fritz
      Müller was not fully appreciated and that it was he who
      had most efficaciously contributed to the confirmation of
      Darwinian theories.

Every animal begins by being _unicellular_, for the egg-cell, the
reproducing cell, common to all, corresponds to a unicellular being.
It is only after fecundation, when it has become an ovum, that this
first cell evolves by dividing itself into consecutive segments,
each of which is a new cell. This phenomenon is analogous with the
multiplication of unicellular beings through division; only, those
segments of the ovum do not separate but constitute a whole under the
aspect of a hollow sphere, called a _blastula_, which is the first
manifestation of a multicellular being. This blastula is formed of
superposed layers, each of which gives birth to specialised organs in
the embryo. The outside layer, or _ectoderm_, produces teguments and
the nervous system; the internal layer, or _endoderm_, gives birth to
endothelial cells, the digestive and internal organs; between those two
layers comes a third, intermediary layer, the _mesoderm_, from which
the skeleton is developed and also the muscle and blood tissues.

The evolution of these layers in Vertebrates was well known, but very
little so in Invertebrates, though it is only through the development
of inferior forms that the origin and general evolution of living
beings can be elucidated. That is why, during many years, the principal
theme of Metchnikoff's researches was the comparative study of the
embryonic layers of inferior animals and the ulterior fate of their
constituting elements. By following this train of thought, he was able
to demonstrate that the development of lower animals takes place on the
same plan and follows the same laws as that of higher animals; thus,
that there is a real communion between all living beings, which is the
concrete confirmation of the theory of evolution.

By their work, Kovalevsky and Metchnikoff contributed to the foundation
of Comparative Embryology. The comparative study of cells produced
from the divers embryonic layers, and observations on the ulterior
development of the functions of those cells, gradually led Metchnikoff
to his theory of phagocytes and to pathological biology. An
uninterrupted thread can be followed right through his life-work, from
the beginning until the end.

In spite of his absorbing work he took great interest in his
surroundings, and during this first stay in Italy he became acquainted
with two interesting personalities, Bakounine the anarchist and
the celebrated physiologist Setchénoff. Both resided at Sorrento.
Kovalevsky and Metchnikoff, who greatly desired to know them, decided
to call on them, after much hesitation.

Bakounine, a giant with a leonine head and a thick mane of grey hair,
struck them as being a fiery enthusiast but an intolerant sectarian,
easily roused; for instance, any small and unimportant local meeting
was enough for him to predict an imminent revolution in Russia. His
theories were epitomised in these words, "We must not leave stone
upon stone"; but when asked what should be built up on those ruins
he could only say, "We shall see later." Elie looked upon him as a
force powerful by its fire and vitality, but thought his mind neither
judicial nor profound.

Very different was the impression produced on him by Setchénoff.
He carried great weight through the depth of his intelligence, his
persuasive eloquence and general thoroughness. He was of a Mongol
type and his features were plain, but his splendid eyes, deep and
intelligent, shrewd and yet kindly, illumined his face with an
unforgettable inward beauty. When Elie went to see him, it was with the
uneasy feeling that his own knowledge of chemistry and physics was very
restricted, having been very superficially acquired during his rapid
passage through the University. In spite of this cause for bashfulness,
a mental compact and exchange of ideas was immediately established
between the two, and a sympathy was born between them which developed
into a lifelong friendship. Elie expatiated upon his plans for the
study of the embryology of inferior animals from the evolution point
of view, and received from the older scientist much encouragement, for
which he never ceased to be grateful.

He worked a great deal during this first stay at Naples, in spite
of periods of great fatigue. As a relaxation, he plunged into
philosophical reading. After Kovalevsky's departure, he joined
Bakounine's circle, the members of which took their meals in a
restaurant which rejoiced in the sonorous name of _Trattoria della
Harmonia_. In the autumn of the year 1865, a cholera epidemic broke
out in Naples. Every one was nervous and depressed, and this general
depression was increased still more by some of the customs of the
country--continuous lugubrious church bells, funeral processions
in which penitents took part, carrying smoking torches and wearing
hoods over their heads with holes for their eyes, etc. Elie, on whom
the epidemic had made a great impression, was even more disturbed by
the death of one of the members of their little circle, a popular
Englishwoman, liked by everybody. She had no fear of cholera and was
bright and merry. But one day she did not come to the _Trattoria della
Harmonia_; she had been struck by the scourge and was dead the next day.

Elie was so struck by her death that his nerves, already very tense,
gave way and he left Naples, being, moreover, worn out with overwork.

He started for Göttingen, for he wanted to begin the study of
Vertebrates under the direction of Professor Keferstein. Keferstein
straightway gave him a valuable lizard specimen to anatomise. Elie was
not good at technique, on account of his nervous temperament; he used
occasionally to lose his patience and his temper, to that point that he
flung his material across the room. It happened so on this occasion;
having completely wasted the valuable lizard, he conceived a still
greater horror of technique and soon left Professor Keferstein for
Henle, the celebrated anatomist. He worked with him for a short time
at the histology of frogs' kidneys, a subject chosen by the Professor.
Soon the young man realised that he was no longer capable of submitting
to school discipline and resumed his independent researches. When he
had to do with those problems which absorbed him he was always able
to conquer his aversion for technique and to do what was required. He
studied the embryology of the green-fly from the genealogical point
of view, and went to Munich for the summer term in order to work with
the celebrated zoologist von Siebold, a typical and venerable old
German scientist. The latter was too old already to be troubled with
pupils, and Elie studied his insect embryology independently; however,
he visited the old man assiduously, and they had long scientific
conversations. Their relations were always extremely cordial, and they
even kept up a regular correspondence for many years.

During his stay in Germany, music was the young man's only recreation.
He did not play any instrument; his parents, discouraged by the failure
of their elder children, had not had him taught, and besides, his
precocious vocation would have left him no time. Yet he certainly had
a natural talent for music, which he passionately loved. He could
only whistle, but with that feeble means succeeded in reproducing
complicated compositions. Having assiduously attended excellent
concerts, he had made himself thoroughly acquainted with classical
music, and Beethoven and Mozart always remained his favourite
composers. His stay in Germany taught him to appreciate the great
capacity for work of the scientists of that country; he admired the
organisation of their laboratories, allowing every force, great or
small, to be utilised and making useful collective work possible in
those complicated researches which demand the collaboration of divers
specialists. On the other hand, he felt a great aversion for the
manners and customs of German students. Their corporations, duels, and
long sittings in beer-houses were distasteful to him; he could not
understand how these coarse "Burschen" could become transformed into
cultivated intellectuals and respectable scientists. People to whom
he expressed this wonder merely said, "Youth must have its fling...."
Moreover, scientists themselves were not particularly courteous to
each other. More than anywhere else personal questions held a foremost
place, and kindliness was rare between colleagues.

After staying some time in Munich, Elie returned to Naples, war having
broken out between Northern and Southern Germany. This time, in order
to spend less on the journey, he took a steamer at Genoa, but with
fatal results, for a storm was raging; he suffered a great deal, and,
when he reached Naples, violent fits of giddiness made him incapable
of doing any work at all for some time. Cholera reappeared, and the
landlady of the rooms he shared with Kovalevsky died of it. Much
depressed, the two started for Ischia, but Elie soon realised with
terror that he was not yet well enough to work; in order to recover
quickly, he went to Cava, a pretty little place, renowned for its
salubrious climate.

There he met Bakounine again, and they saw a good deal of each other in
a friendly way. Bakounine nicknamed him "Mamma" because of his almost
maternal attentions, a nickname which, for the same reason, was given
him later, quite independently, by other intimates. Yet, though their
relations were cordial and even affectionate, there was not really much
in common between the two. Elie thought Bakounine's ideas superficial,
and disliked his sectarian mentality; they ultimately drifted apart.

His health having gradually recovered owing to the rest, he returned
to Naples in the autumn, after the epidemic had abated, and at last
resumed his work.

Whilst studying the history of the development of Cephalopoda he found
that they had embryonic layers similar to those of Vertebrates; this
was the first time that the fact was established. It was extremely
important, for it constituted a concrete and indisputable proof of
the existence of a genetic connection between inferior and superior
animals. Metchnikoff chose this subject for his thesis, and, having
completed his researches, he returned to Russia in 1867.

By this time he had made great use of his three years' stay abroad.
Though he had not showed himself a docile pupil, yet he had become
initiated into the organisation of scientific work in Germany; he had
carried out independent researches and had been able to choose with
full knowledge the future path of investigations which he was to pursue
for many years in the field of Comparative Embryology.

Already the observations he had made had in themselves a real
importance. For instance, his studies in divers specimens of the worm
type, a type which offers very heterogeneous forms, had permitted him
to establish links of continuity between certain groups among them.
Whilst studying those animals at Giessen in 1865, he had discovered
the capital fact which proved to be the starting-point of all his
future work--the _intercellular digestion_ of an inferior worm, a land
planarian, the _Geodesmus bilineatus_. He had compared this digestion
with that of the superior Infusoria and had seen in it one more proof
of the genetic connection between the type of the Protozoa and that of
worms.

He did not then realise the full bearing of this observation, which
really constituted the basis of his future phagocyte theory; this was
only to appear eighteen years later.

He had also made researches on numerous specimens of insects and on the
scorpion, establishing the fact that they all had embryonic layers;
he concluded that he was "entitled to extend the theory of embryonic
layers to Arthropoda."

Finally, he had discovered embryonic layers similar to those of the
Vertebrates in inferior Invertebrates, the Cephalopoda (Sepiola). This
established a link of continuity between the higher and lower animals.




                              CHAPTER XII

  Petersburg--Baer prize--Return home--Friendship with Cienkovsky
  --Odessa--Naturalists' Congress at Petersburg--Departure from
  Odessa--Zoological Lecturer's Chair at Petersburg--Messina--Enforced
  rest--Reggio--Naples--Controversy with Kovalevsky--Visit to the
  B. family--Mlle. Fédorovitch--Educational questions--Difficulties
  of life in Petersburg.


During his stay abroad, Metchnikoff had successfully carried out
several researches, and this allowed him to apply for a post of
_docent_ at the new University of Odessa, which he had chosen on
account of its proximity with the sea and its marine fauna. Whilst
awaiting the result he went to Petersburg in order to pass his thesis
and to prepare himself to become a professor. He received a pleasant
welcome, for his lively and sociable disposition had made him many
friends. The brothers Kovalevsky, with whom he was already on friendly
terms, offered him hospitality; he also made the acquaintance of
Professor Békétoff, and soon became a member of his family circle.

He was well received everywhere, for his scientific precocity excited
general interest. He was even elected _magister_[10] by the Faculty,
without having to pass an examination, on account of the work he
had done. He and Kovalevsky halved Baer's first prize, and they
were invited and treated with the utmost kindness by Baer himself.
Metchnikoff had certainly entered upon a successful phase; his friends
nicknamed him "the star." As soon as he was made a _magister_, he
received his appointment at the Odessa University, and, the holidays
drawing near, he was at last able to return to his home. Needless to
say how joyfully and lovingly he was received by his family. He spent
two months with them, utilising his leisure in preparing himself to
teach.

  [10] A degree preceding that of Doc.Sc.

In his hurry to arrive in Odessa in good time in order to take his
bearings before starting his lectures, he went there much too soon and
found nobody at the University; he then decided to go to the Crimea for
some preliminary studies on the fauna of the Black Sea. Before long,
he made the acquaintance of the celebrated botanist Cienkovsky, who
invited him to stay in his villa. Though the scientist was already 46
years old and Elie only 22, they soon became fast friends. Cienkovsky
was a man of great European culture; passionately fond of science as
he was, his critical mind submitted everything to a close analysis.
He took great interest in young Metchnikoff and showed him a marked
predilection, but that did not prevent him from criticising him
severely. He reproached him with a lack of self-control, and undertook
the paternal task of civilising the impulsive, fiery, sometimes even
violent young man. He preached to him tolerance towards the opinions of
others, a strict self-discipline, and the absolute necessity of bowing
to certain social conventions against which Elie blindly rebelled.
Cienkovsky acquired great prestige in his young friend's eyes; years
later, even, Metchnikoff took pleasure in quoting his axioms and in
trying to conform with them.

He worked with ardour during his stay in the Crimea; though the
heat was great, 50° C. (122° F.) in the sun, he undertook zoological
excursions and surprised every one by his endurance and energy.

At the end of the holidays, he returned to Odessa and began his
professorate with much zeal and success. His lucid, living lectures
stimulated his pupils, third-year students, who were all older than
himself. Friendly relations soon reigned between them and their young
lecturer; he organised practical studies, and his laboratory became a
very active centre of work.

Thus everything was going well, and perhaps he might have remained at
Odessa for a long time if it had not been for the following incident,
due to his passionate and intolerant disposition. A Congress of Russian
naturalists was to take place in Petersburg at the end of the year
1867. Elie eagerly wished to attend it as a delegate and took steps
for that purpose; this brought him into conflict with his chief, who
desired the mission for himself. Knowing that the old Professor had no
real scientific interests, Elie thought himself justified in insisting,
and counted upon Cienkovsky's support, but the latter was of opinion
that the younger man should give way. Elie, becoming more and more
excited, lost all sense of proportion and committed the grave error
of telling his pupils about what he considered a serious injustice.
The latter, out of sympathy for their young lecturer, hooted the old
Professor, which naturally embittered the quarrel. However, all the
agitation ended in both zoologists being sent to the Congress in the
quality of delegates.

When he reached Petersburg, Elie hurried to the house of his friends
B----, who received him with open arms; it was a great joy to him
to find himself in friendly surroundings after the recent strife.
Impulsive and impressionable as he was, the disagreeable incidents
he had traversed made him yearn to leave Odessa, a desire which was
to be promptly realised. His communications had great success at the
Congress; the President even invited him to read a paper at the general
meeting; but, though strongly attracted by this proposal, which would
have allowed the young scientist to expose his ideas on the comparative
development of the embryonic layers, he refused it, considering that
that complicated question was not yet sufficiently matured.

Nevertheless, the Congress had brought him into prominence and was
the cause of his obtaining a Professorship of Zoology at Petersburg.
Moreover, he had the additional good fortune of being given a
scientific mission and went abroad to work until the autumn term.

He went to Naples in the spring of 1868, thinking to find Kovalevsky
there, instead of which he found a letter from his friend awaiting him.
The latter had had to go to Messina for urgent embryological work and
begged Elie to look after his wife and new-born child. Metchnikoff did
so most willingly until he was able to send them off to Messina. He
himself followed soon after, for Kovalevsky wrote him that zoological
specimens and conditions of work were far better at Messina than
Naples. This time, Metchnikoff undertook the study of Sponges and
Echinodermata. The two friends worked unceasingly, but Elie's sight was
too weak for such excessive fatigue; he was again obliged to interrupt
his studies for a while, and during that period of enforced rest he
felt for the first time the need of a sentimental affection in his life.

He dreamed of a helpmeet who would conform with his tastes. At
Petersburg he had become very fond of Professor B.'s young daughters,
the eldest of whom was about thirteen years old, and he wondered if he
could not train one of those little girls to become the realisation of
his ideal. He was too active by nature, however, to linger very long
over reveries or over a prolonged rest; he therefore undertook a short
journey through Reggio and Calabria, on his way towards Naples.

His eyesight being now restored, he began work again as soon as he
arrived. This period, however, was not a pleasant one: to begin
with, he obtained in the study of Ascidia a result which differed
considerably from that obtained by Kovalevsky,[11] and this scientific
controversy grieved and preoccupied them both. Besides, Elie's nerves
suffered from his constant anxiety about his eyes, the tropical heat
and the noisy life of Naples. Incessant serenades used to keep him
awake at night, and, on one occasion, his exasperation reached such a
point that he poured a bucket of water over the head of some persistent
musicians. Tired with all these things, he left Naples for Trieste,
where he carried out successful researches into the transformations of
Echinodermata, from the point of view of Comparative Embryology and
genetic connections between inferior animals.

  [11] The latter affirmed that the nervous system of Ascidia
       originated from the upper layer, whilst Elie believed that
       it was the lower layer which gave birth to it. It was
       Kovalevsky who was right, as Elie himself declared later.

Having obtained results which interested him, he returned to Russia and
joined the B. family in the country, near Moscow. Their young friend
Mlle. Fédorovitch, whom he had already met in Petersburg, was staying
with them, and she and Elie became very good friends. His affection for
the B. children led him to ponder over general educational questions.
He was struck for the first time by the lack of harmony in human
nature, which was due, he thought, to the considerable difference
between the organism of the child and that of the adult, a difference
which does not exist in animals to the same degree.[12] As soon as
he returned to Petersburg he tried to study this subject, and made
comparisons between the brain of a man and that of a dog at various
ages, but without result.

  [12] He ultimately developed these considerations in a paper
       entitled _Education from an Anthropological Point of View_,
       of which mention will be made hereafter.

He was not long in realising that the conditions of work in his new
post were extremely unsatisfactory. He had no proper laboratory and
had to work between two specimen cases in a non-heated zoological
museum; there was no room for practical work. All his enthusiasm, all
his aspirations towards scientific activity and rational teaching
struck against indifference, lack of organisation, and lack of means.
He protested with his usual vehemence, but could obtain nothing; being
equally unable to adapt himself to his uncongenial surroundings,
he found himself getting more and more discontented and unnerved.
Moreover, his everyday life was most uncomfortable, for he wished to
do without servants, on principle and in order to economise, and to do
his household work himself; but he soon tired of taking the necessary
care of his rooms, which became a regular chaos. He left off preparing
his own meals and went out for them to an inferior restaurant in the
neighbourhood. Yet, in spite of all his efforts and privations, he
never seemed to make both ends meet. He resigned himself to giving
lessons at the School of Mines in order to increase his resources; the
school was a long way off, he had to walk the distance in the coldest
weather in order to lecture to students who did not interest him. The
work wearied him without giving him any moral compensation. Altogether,
the life in Petersburg, on which he had founded great hopes, brought
him nothing but disappointments and made him become more and more
pessimistic and misanthropical.




                             CHAPTER XIII

  Slight illness--Engagement to Mlle. Fédorovitch--Marriage--Illness
  of the bride--Pecuniary difficulties--Spezzia--Montreux--Work in
  Petersburg University--The Riviera--Coelomata and Acoelomata--St.
  Vaast--Panassovka--Madeira--Mertens--Teneriffe--Return to Odessa--Bad
  news, hurried journey to Madeira--Death of his wife--Return through
  Spain--Attempted suicide--Ephemeridæ.


It was only in the house of his friends the B.'s that Elie felt at his
ease. He was devotedly fond of their children, whom he used to take for
walks on Sundays and to the theatre now and then; he was always ready
to read to them and to indulge them in every possible way.

He continued to entertain the dream of marrying one of them some day,
and was particularly interested in the eldest, a girl of thirteen,
intelligent, gifted, and lively; however, as he knew her better,
he realised the incompatibility of their respective tempers, an
incompatibility which brought about frequent disputes. These were
generally smoothed down by a mutual friend, Mlle. Fédorovitch, who
invariably showed Elie a marked and cordial sympathy. He became ill at
this juncture and she nursed him with a devotion which brought them
together even more, as will be seen from the following letter to his
mother:

  DEAR MOTHER--I have just had an inflammation of the throat which
  lasted two weeks; it is quite gone now and I would not even have
  mentioned it to you if it had not been connected with what follows.

  When I fell ill, the B.'s, knowing me to be alone and uncared for,
  brought me to their house. During my stay with them, I acquired the
  conviction that my darling little girls did not love me, especially
  the eldest, who interested me even more than her three sisters....
  The dreams I told you of have vanished!

  It was a grief to me, for, apart from my scientific interests, I
  cherished them more than anything. I have no acquaintances and do
  not require any, but I long to have some one with me to whom I could
  become attached and who could share my pleasures and leisure.

  My grief would have been greater still if I had not seen that
  Ludmilla Fédorovitch, whom I mentioned to you this summer, showed me
  much sympathy in all my troubles.

  We were already very good friends, and have now drawn nearer
  together; who knows? perhaps the 800 roubles which are going to be
  added to my salary will be very useful.

  I will keep you informed of everything, dear Mother, for I am sure of
  your sympathy; I love you better than the whole world and I have full
  confidence in you.

  Au revoir, dear Mother, I kiss your hands.--Your

                                                ELIE METCHNIKOFF.

Mlle. Fédorovitch became ill in her turn; the sympathy which Elie
showed her on this occasion brought them still nearer to each other,
and he soon decided to marry her. He informed his mother of this; much
alarmed, she tried to dissuade him, for she feared that by marrying a
girl in delicate health, her son would be assuming too heavy a task in
his difficult circumstances.

He answered as follows:

  I received your letter to-day, dear Mother. It grieves me very much.
  My project inspires you with doubt, you counsel prudence and, though
  you say you believe me to be reasonable, yet you fear that I am
  acting on an impulse. If I really am reasonable, why fear a blind
  impulse? On the other hand, if I am blindly carried away, it is not
  likely that I shall listen to reason.

  I did tell you that I had great affection for the B. girls, and it
  was true. But did I ever tell you that they had the same for me? You
  are mistaken in thinking that I did not like Ludmilla Fédorovitch at
  first. I was not in love with her but we were very good friends, and
  whilst I did not consider her as my feminine ideal, I was sure of her
  absolutely honest, loyal, and kindly disposition. The very fact that
  I knew Ludmilla for a long time before I thought of marrying her,
  should prove to you that there is some chance of my being neither
  blind nor partial.

  Her love for me is beyond doubt, as you will see when you know her.

  I also am very fond of her, and that is a solid basis for future
  happiness.

  Yet I will not answer for it that we shall spend our life like a
  pair of turtledoves. A rosy, boundless beatitude forms no part of my
  conception of the distant future.

  Yet I do not see the necessity of waiting till I become a thorough
  misanthrope, and I am already inclined that way.

  Please do not believe that, if I do not dream of a rosy happiness it
  is that I feel none at all; that is not the case; I am in a happy
  medium.

  I like Ludmilla and I feel comfortable with her; but at the same
  time I preserve the faculty of feeling every trouble and worry in
  life. I do not at all think that it is enough to love in order to be
  happy. Therefore I have begun to take steps to obtain a Professor's
  chair, and I am very desirous of being successful in that financial
  operation.

Soon after that, he wrote the following letter to his mother:

  DEAR MOTHER--In my last letter I had already spoken to you of
  Ludmilla Fédorovitch. I can now give you information about her which
  will surely interest you.

  She is not bad-looking, but that is all. She has fine hair; her
  complexion is not pretty. We are about the same age, she is a little
  over 23. She was born at Orenburg; then she lived for a long time
  with her family at Kiahta (Siberia), after which she was abroad for
  nearly two years and finally settled in Moscow. Ludmilla, or Lussia,
  was, as you remember, a very zealous intermediary between me and the
  B. girls to whom I was so attached.

  She loved me already then, though she said to herself that I had too
  much affection for the B. children ever to return her feelings.

  And she was perfectly right, as long as my affection for those
  children lasted.

  But, when it ceased, I naturally took more notice of Lussia's
  sympathy for me, and I am not surprised that I have acquired much
  affection for her.

  She has faults which must seem graver to me than to you, but what is
  to be done?

  Fortunately she herself sees them. The greatest of her faults is a
  too great placidity, a lack of vivacity and initiative; she adapts
  herself too easily to her surroundings. But, being placid, she is
  also firm; she can bear a great deal whilst preserving complete
  self-control. She is extremely kind and good-natured; I have not yet
  found a vulgar trait in her character.

  I have told you of her faults, you must therefore not think me
  partial if I find qualities in her.

  The fact is--and I cannot forget it--that always, when I had any kind
  of trouble, she soothed me by her attitude towards me.

  Even though I have dark previsions for the future (as you know, I am
  not given to seeing life through rose-coloured glasses), I cannot
  help thinking that by living with Lussia I should become calmer, at
  least for a fairly long time.

  I should cease to suffer from the misanthropy which has invaded me
  lately.

  I intend to have no children--it is an embryologist who is speaking.
  On the contrary, I want to preserve the utmost liberty. Nevertheless,
  one must conform with certain legal conventions, which will probably
  take place in January.

  Lussia has no fortune, but we shall be entirely guaranteed by the
  increase in my salary.

  It is very regrettable that the event should be retarded by the
  customary formalities; in any case it will certainly end by taking
  place.

  I beg you to write to me, dear mother that I love, anything that
  comes into your head _à propos_ of my affair.

  Rejoice that I am now very happy and wish that it may last.

  I ask the same of Papa, whom I beg you to salute from me. I embrace
  you, dear Mamma, and I remain your very affectionate son,

                                                  E. METCHNIKOFF.

As Elie learnt to know his fiancée better, he became more and more
attached to her. Their happiness seemed likely to be complete, but a
cruel Fate had decided otherwise. The girl's health was not improving:
her supposed bronchitis was assuming a chronic character. Yet the
marriage was not postponed, and the bride had to be carried to the
church in a chair for the ceremony, being too breathless and too weak
to walk so far.

Elie did his utmost to procure comforts for his wife, and hoped that
she could still be saved by care and a rational treatment. It was the
beginning of an hourly struggle against disease and poverty; his means
being insufficient, he tried to eke them out by writing translations.
His eyesight weakened again from overwork, and it was with atropin
in his eyes that he sat up night after night, translating. There was
but one well-lighted room in his flat, and he turned it into a small
laboratory for the use of his pupils; his own researches he had to give
up, his time being entirely taken up by teaching and translations.

He hid his precarious position from his parents in order not to add
to their heavy expenses nor to confirm their previsions concerning
his marriage. His wife's illness, the impossibility of carrying on
scientific work, the lack of friendly sympathy to which he thought
himself entitled, all this weighed on him, making him bitter,
suspicious, and distrustful; he thought himself persecuted. The
situation became intolerable and, in spite of his pride, he forced
himself to apply for a subsidy to take his wife abroad and to go on
with his researches. Having obtained it in 1869, he immediately left
Petersburg, which he now hated.

Youth is elastic: the young couple started full of joy, gay as
children, and ready to forget all their trials. Alas, it was not for
long: having halted at Vilna in order that the patient should have a
rest, she had an attack of hæmorrhage of the lungs, to the great alarm
of her husband, who nevertheless did his best to reassure her. They
continued the journey as soon as her condition allowed it, only to be
interrupted by another relapse. At last they reached Spezzia, chosen on
account of the climate and the marine fauna.

Little by little, Ludmilla Metchnikoff's health improved and her
husband was able to resume work. He studied aquatic animals in view
of the genealogy of inferior groups, and, amongst others, studied the
Tornaria, which was believed to be the larva of the star-fish. However,
to his astonishment, he ascertained that, in spite of great similarity,
it was not the larva of an Echinoderm, but that of one of the
Balanoglossi, of the worm type. This fact established a link between
the Echinodermata and worms, a very important result from the point of
view of the continuity of animal types.

Metchnikoff felt his courage returning and also his natural high
spirits. His wife, who was a clever draughtswoman, helped him with the
drawings for his memoir, and both felt happy and contented; this stay
at Spezzia was a real oasis in their life.

When the heat became excessive they went to Reichenhall, a summer
resort prescribed by the doctor. There, Metchnikoff completed his
previous researches on the development of the scorpion, and finally
established the fact that this animal possesses the three embryonic
layers which correspond to those of the Vertebrates.

As his young wife's health was still too precarious to allow her
to spend the winter in Russia, Metchnikoff, obliged to return to
Petersburg, installed her at Montreux and asked his sister-in-law,
Mlle. Fédorovitch, to stay with her. The enforced separation
deeply grieved the young couple, whose only consolation was daily
correspondence.

Metchnikoff resumed a life of hard work; he was now an _agrégé_ at
the Petersburg University and had to leave the School of Mines; this
diminished his resources, but at the same time he obtained an extra
salary of 800 roubles as Extraordinary Professor. His position in the
University was nevertheless very difficult, for his situation was
coveted by different parties with which he had nothing to do. They
wanted it for one of their adherents. His devoted friend Setchénoff,
Professor of Physiology, then thought of proposing him to the Faculty
of Medicine as a Lecturer in Zoology, and whilst Metchnikoff awaited
the result of his efforts, he obtained leave to go to the seaside to do
research work.

He joined his wife and took her to San Remo and to Villafranca. Her
health had improved and she was even able to take part in his work.
He was engaged in studying Medusæ and Siphonophora, animals which
interested him, not only from the point of view of the origin of
embryonic layers, but also from that of general morphology, for he
was still pursuing the problem of genetic links between animals. He
had already been able to prove the presence of embryonic layers in
many inferior animals; moreover, he had found, while studying the
metamorphoses of Echinodermata, the proof that the _structural plan_,
hitherto considered immutable, could become transformed in course
of development. Thus the bilateral plan of the larva of Echinoderma
becomes a radial plan in the adult. The structural plan therefore
is not an absolutely differentiating character, since specimens of
the same type can show a different plan according to their stage of
development. One of the genetic questions still unsolved was that of
the body cavity. Always present in higher animals, it is totally absent
in certain lower groups, such as Sponges, Polypi, and Medusæ. It was
being questioned whether their dissimilar morphological characters
did not correspond with a duality of origin separating animals which
possessed a body cavity (Coelomata) from those which did not
(Acoelomata).

Kovalevsky, it is true, had observed that the body cavity of many
animals (Amphioxus, Sagitta, Brachiopoda) took its origin in the
_lateral sacs_ of the digestive cavity, sacs which detach themselves
from it in order to form the body cavity. But, in order to establish a
genetic connection between those animals that have a body cavity and
those which are devoid of it, it was necessary to show the homology of
corresponding organs in both groups.

Through his researches on the development of Coelomata
(Echinodermata) on the one hand and Acoelomata (Ctenophora and
Medusæ) on the other, Metchnikoff succeeded in proving that the lateral
sacs of the digestive cavity which give birth to the body cavity of the
Coelomata (Echinodermata) correspond to the canals and vaso-digestive
sacs of the Acoelomata (Ctenophora and Medusæ). The difference
consists in that the latter do not detach themselves in order to form a
body cavity, which is therefore lacking.

The result of his researches satisfied Metchnikoff; moreover, he began
to feel again hopeful of his wife's recovery. The only dark spot was
that Setchénoff's efforts had failed. Metchnikoff was not appointed
by the Faculty of Medicine, for it was found advisable to replace the
Chair of Zoology by one on Venereal Diseases. On the other hand, he
was nominated for the Odessa University, supported by Cienkovsky and
unanimously elected.

As he only had to go to his new post in the autumn, he went for the
summer to St. Vaast in Normandy to study Lucernaria; unfortunately the
stay was not a success; the weather was cold and the sea very rough,
which made the Lucernaria impossible to find. Life conditions were very
difficult, all the male population being at sea and the women being in
the fields. In order not to waste this journey he studied Ascidians,
and found that he had previously been mistaken at Naples when he
thought that the nervous system of those animals originated from the
lower embryonic layer. Kovalevsky had been right in affirming the
contrary, and Elie hastened to write to tell him so.

St. Vaast, open to every wind, was not favourable to the patient, and
Metchnikoff had to take her away. They went to Russia to stay with her
parents and then to Panassovka. The doctors having advised a course of
treatment by "koumiss," or fermented mare's milk prepared in a special
way by the Tartars, Elie engaged a Tartar servant specially for that
purpose, but in vain. In spite of every treatment, his wife's health
was steadily growing worse. The cold at St. Vaast had been followed
by such a dry heat in Russia that, in order to procure a little
coolness for the patient, they had to spread wet sheets around her. She
constantly had high temperatures and frequent attacks of hæmorrhage.
It was obvious that she must leave Russia, and Metchnikoff, obliged to
rejoin his post at Odessa, asked Mlle. Fédorovitch to go with her to
Montreux.

The separation was all the harder that all hope of recovery was
beginning to wane. The patient, however, had been told of the magical
effect of Madeira in cases of tuberculosis, and she clung to the idea
as to a plank of safety. Elie resolved to take her there. He set to
work with renewed ardour in order to obtain the sum necessary for
the journey; in spite of all his self-denial, his normal resources
would not have sufficed, and he had recourse to translations and
literary articles. He had a theme ready, which he developed in a paper
called _Education from the Anthropological Point of View_--in fact a
preliminary sketch of his ideas on the disharmonies in human nature.
In it, he analysed the disharmonies due to the great difference of
development between the child and the adult: whilst the young of
animals are very rapidly able to imitate the adults and to live like
them, the man-child is incapable of it. His brain, especially in
civilised races, demands a long period of development in order to equal
that of the adult, whilst certain instincts in the organism mature,
on the contrary, long before their function is possible. Moreover, a
child's sensibility is extremely developed whilst his will is by no
means so. These causes provoke suffering and a series of regrettable
consequences.

Apart from frenzied efforts and unceasing labour, Metchnikoff was going
through a painful moral crisis, due to the impossibility of making
his conduct accord with his convictions. Party intrigues continued
to be rife at the Odessa University: Poles were being persecuted
by Nationalists; one professor was refused admission on account of
his Polish nationality, and Cienkovsky resigned by way of protest.
Metchnikoff shared his views and longed to follow his example, but was
prevented by his lack of means and felt it deeply. It also went against
his conscience to ask for leave as frequently as his wife's condition
made it necessary.

She wished to see her parents once again before going to Madeira, and
he took her to Russia for the last time: she never saw her family again.

At last they were able to start. The long journey was very fatiguing,
the sea voyage was rough, but, when she landed in Madeira, the patient
thought herself saved. The very next morning Metchnikoff started
feverishly on a voyage of discovery. Nature on the island was extremely
beautiful; alone the sight of numerous sick people reminded him of
suffering and death. The words "a flower-decked grave" haunted his
mind, and a growing despondency warned him that he had nothing to
expect from this luxuriant spot. From the aspect of the rocky coast,
beaten by the waves, he realised that the beach fauna must be very
poor; his only refuge, research work, was likely to be denied him.

He was advised to hire a small house, which would be cheaper than
a boarding-house, and he did find a pretty furnished villa with a
garden; it was beyond his means, but a young Russian named Mertens,
who had been a fellow-traveller, proposed to share it with them. The
arrangement proved highly satisfactory, and Mertens, at first merely an
agreeable neighbour, became a close friend.

Before leaving for Madeira, Metchnikoff had obtained a scientific
mission and a subsidy from the Society of Natural Science Lovers of
Moscow, and felt it a moral obligation to obtain some results. The
scantiness of the marine fauna was a bitter disappointment; he had
to fall back upon what little he found, and embarked on the study,
hitherto unknown, of the embryology of Myriapoda. But this research
work brought him a new source of torment instead of satisfaction: he
could not master the technique, which proved to be very difficult, and
this irritated him; his failures disappointed him, made him vexed with
himself; his nerves, already strung to the highest point by suffering
and anxiety, made the disappointment unbearable. On the other hand,
the external aspect of life formed a striking contrast with the state
of his mind. A wealth of natural beauty, all flowers and perfumes, in
an incomparable site, congenial surroundings and home comforts formed
the frame for these two young lives, of which one was waning whilst the
other was spent in a useless struggle to save it.

Metchnikoff's natural pessimism was growing under the influence of
these painful circumstances. His conception of life was a sombre
one; he said to himself that the "disharmonies" of human nature must
infallibly end in a general decadence of humanity. He set forth
his reflections in an article entitled _The Time for Marriage_, in
which he discussed the following concrete fact: With the progress of
civilisation and culture, the time for marriage recedes gradually,
whereas puberty remains as early as before; the result is that the
time between puberty and marriage is becoming longer and longer,
and constitutes a growing period in which there is no harmony. The
statistics of suicides prove that there is a close connection between
them and the period of disharmonies.

Whilst he worked, his wife tried to make use of her leisure: she
interested herself in poor children, sketched flowers, read novels ...
life flowed peacefully in spite of the underlying drama.

Yet the thought that he was not fulfilling his obligations was
intolerable to Metchnikoff. He thought of resigning and founding a
small book-shop at Madeira in order to be independent and not obliged
to leave his wife, but lack of funds made this plan impossible. In his
search for new resources, he went to Teneriffe to look for a subject
for an article. He met with several disappointments on this trip; yet
he saw the Villa Orotava, with its celebrated giant dragon-tree, which
had already then been brought down by a storm. He also visited the
Caves of the Guancios, the primitive inhabitants of the Canary Islands.
Having gathered the necessary observations, he hastened to return to
Madeira, where months passed without bringing any change.

The book-shop idea was abandoned as being impracticable and Metchnikoff
had to return to Odessa, asking his sister-in-law to come to Madeira
in his place. When she had arrived, he confided the two girls to
Mertens and to the care of the devoted Dr. Goldschmidt, and went away
conscious of the uselessness of his efforts and more deeply pessimistic
than ever.

When he reached Odessa, in October 1872, he found there his friend
Setchénoff, whom he had previously proposed for a Physiology Lecturer's
chair, and whose affection was a great comfort to him at this sad time.
The correspondence between him and his wife during that period is full
of an infinite tenderness, as if they felt the supreme separation
coming near, and yearned to express their mutual love.

At the end of January 1873, between two classes, Metchnikoff received
a letter from his sister-in-law telling him to come in haste if he
wished to find his wife still living. He delivered his lecture like
an automaton, then went to obtain his leave and hurried off. He
accomplished the whole journey without a break. On arriving at Madeira
he found his wife so changed that he scarcely knew her, and it was
only through sheer force of will that he kept his alarm from her. She
suffered so much that she had to be given morphia constantly and could
no longer leave her bed.

Metchnikoff himself was in very poor health; his eyes were so sensitive
from overwork that he had to remain in the dark, only going into the
garden at dusk to observe spiders and snails. Time was progressing
slowly and miserably, and bringing nothing but anxiety as to the means
to support this sad existence. Metchnikoff had hoped to receive the
Baer prize for a zoological work, but did not obtain it: it was refused
on the pretext that his memoir had been presented in manuscript
instead of being printed. In reality, the German party had wished to
give it to a fellow-German.

A friend of his, who sent him the bad news, offered to lend him 300
roubles, and Metchnikoff accepted; he could now think of nothing but
holding out till the end.

One morning the patient's condition suddenly became much worse. The
doctor was sent for in a hurry and declared that it was now a question
of a few hours.... When Metchnikoff went back to his wife he found her
with eyes wide open and so full of mortal anguish and utter despair
that he could bear it no longer and went out hastily, not to show her
his dismay.

This was his last impression; he never saw her again.

Only half conscious, he walked up and down the drawing-room, opening
and closing books without seeing them, his mind full of disconnected
pictures; he wondered to himself how his family would hear the news.
Time passed without his realising it. Then his sister-in-law came to
tell him that all was over. This was on the 20th April 1873.

Metchnikoff's feelings were complex: a mixture of crushing despair and
of relief at the thought that the terrible agony was at last ended....
During the whole of the sad first night he sat with his sister-in-law
in a distant room, talking of those things which are only mentioned
in moments such as these. When Dr. Goldschmidt came in the morning
to offer Metchnikoff his sympathy and help he found him apparently
almost calm. Metchnikoff asked him to make a post-mortem examination
of the deceased and to look after her sister. A Scottish minister
came to bring religious comfort and to exhort him to look there for
consolation. Metchnikoff thanked him, but firmly assured him that it
was not possible to him.

The funeral took place two days later; he did not attend it and did not
see the corpse. Immediately after the funeral he left Madeira with his
sister-in-law. Being no longer anxious to economise, he took with him
a sick young Russian who wished to see his mother again and could not
afford the journey.

After the catastrophe, Metchnikoff felt incapable of thinking of the
future, his life seemed cut off at one blow; he destroyed his papers
and reserved a phial of morphia, without any settled intention. They
journeyed back through Spain; it was during the Carlist insurrection,
and several episodes on the way distracted their attention. Elie and
his sister-in-law reached Geneva, where they found Leo Metchnikoff
and several relations, among whom he seems to have recovered himself.
He even related some of their travelling experiences, meetings with
Carlists, frontier incidents, etc., with some spirit. But his apparent
calm concealed black despair.

He said to himself: "Why live? My private life is ended; my eyes are
going; when I am blind I can no longer work, then why live?" Seeing no
issue to his situation, he absorbed the morphia. He did not know that
too strong a dose, by provoking vomiting, eliminates the poison. Such
was the case with him. He fell into a sort of torpor, of extraordinary
comfort and absolute rest; in spite of this comatose state he remained
conscious and felt no fear of death. When he became himself again, it
was with a feeling of dismay. He said to himself that only a grave
illness could save him, either by ending in death or by awaking the
vital instinct in him. In order to attain his object, he took a very
hot bath and then exposed himself to cold. As he was coming back by the
Rhone bridge, he suddenly saw a cloud of winged insects flying around
the flame of a lantern. They were Phryganidæ, but in the distance he
took them for Ephemeridæ, and the sight of them suggested the following
reflection: "How can the theory of natural selection be applied to
these insects? They do not feed and only live a few hours; they are
therefore not subject to the struggle for existence, they do not have
time to adapt themselves to surrounding conditions."

His thoughts turned towards Science; he was saved; the link with life
was re-established.




                              CHAPTER XIV

  Anthropological expedition to the Kalmuk steppes--Affection of the
  eyes--Second expedition to the steppes--The eggs of the _Geophilus_.


After the misfortune which had befallen him Metchnikoff placed his
only hope in work, and the condition of his eyes was therefore for
him a source of great preoccupation. He applied to the Petersburg
Geographical Society for an anthropological mission in order to
undertake researches less trying to his eyesight than microscopical
work.

As he went deeper into anthropology, he was struck by the fact that
this science lacked a leading thread and was guided by no general idea
but reduced to mere measurements, very precise and detailed, it is
true. Metchnikoff wondered whether it would not be advisable to apply
to anthropology the methods used in embryology and to establish an
analogy between the diverse human races and the different ages of the
individual. In order to solve this problem he had thought at first of
visiting the Samoyedes as being the most primitive of the aboriginal
peoples of Russia. But the project was not realisable and he determined
to visit, at his own expense, the Kalmuks of the Astrakhan steppes,
also a primitive Mongol race.

Before his departure he went to see his family and that of his late
wife. Long afterwards his sister-in-law, Mlle. Fédorovitch, wrote me
the following account of that interview:

  He was still suffering from an inflammation of the eyes. This man,
  whom I cannot picture to myself without a microscope or a book, was,
  at that sad period of his life, reduced to complete inactivity.
  We had always been struck with his power of becoming absorbed in
  scientific reading, even during meals; it inconvenienced no one, for
  he heard at the same time the conversation that was going on and even
  took part in it from time to time. Now, the day after his arrival,
  I came to call him to tea and found him seated in his darkened room
  with scissors in his hands and the floor around him littered with
  small pieces of paper ... such was the occupation to which he was
  reduced.

  He told me that, if I liked, he would come to live in Moscow and
  devote his life and his work to our family. I refused and told him
  why; my refusal grieved him, but I was right. Besides a feeling of
  generosity, his offer was actuated by a desire for an immediate
  object in life. Soon after that, he started for the Kalmuk steppes in
  order to undertake anthropological researches. I was often haunted by
  the thought of his sad figure in the midst of the steppes.

The journey was difficult and fatiguing. Metchnikoff did not know the
Kalmuk language and had to depend on interpreters. From the very first
he was painfully impressed by the brutality of the Russian officials
towards the natives. At every halt the Kalmuks declared that they had
no horses; the Cossack who convoyed Metchnikoff would then begin to
swear and to play with his "nagaika" or leather-thonged whip, and the
required horses appeared as by magic. After a while Metchnikoff became
used to such scenes and looked upon them as a custom of the country.
He found it more difficult to put up with the indescribable dirt, the
smell of mutton fat which impregnated the food, and the continual
barking of dogs during the night, details which destroyed the charm and
poetry of primitive life. In spite of these unfavourable conditions,
Metchnikoff worked indefatigably. The physical measurements of the
Kalmuks led him to conclude that the development of the Mongol race
was arrested in comparison with that of the Caucasian race; he found
that all the relative proportions of the diverse parts of the Kalmuk
skeleton corresponded with that of youth in the Caucasian race: a large
head, a long torso, short legs, absolutely the relative dimensions of
our children. This conclusion was further confirmed by the structure of
the eyelid in the Kalmuks, of which the fold (epicanthus) in the adult
corresponds with that of the fold of the eyelid in our children.

These interesting results somewhat raised Metchnikoff's _moral_,
the more so that his eyesight began to improve; he returned to
Odessa but found that he was still unable to use a microscope. He
therefore decided to go back to the steppes in order to proceed with
his researches, and, this time, began his journey by the Stavropol
province. The steppes there are very fine, with tall, luxuriant grasses
and a profusion of flowers filling the pure atmosphere with perfume;
the infinite space and absolute calm offer a peculiar and powerful
charm. But the population is depressed and apathetic, as is the case
with that of the Astrakhan steppes. The reason must be that the Kalmuks
consume milk which has undergone alcoholic fermentation, and that
provokes a slight but chronic intoxication. Yet a few among them are
extremely intelligent and of fairly high culture. Thus, in the course
of his ethnographical researches Metchnikoff came across a priest
(bakshâ) who imparted to him such instructive facts on the principles
of the Buddhist religion and on the organisation of its clergy that he
even planned to go with him to Thibet, where no stranger can penetrate
without the help of an adept. This plan, however, was never executed.

After he had collected numerous anthropological data, Metchnikoff went
again to the Astrakhan steppes in order to verify and to complete his
observations of the preceding year. Whilst traversing some oases where
the Russians were making experiments in artificial forestry, he had the
pleasant surprise of finding some Myriapoda (_Geophilus_) bearing a
number of eggs. The history of the development of those creatures was
still unknown--a notable lacuna in embryology. Delighted at the idea
of filling it, Metchnikoff did not hesitate to undertake a long and
difficult extra journey and repaired to Astrakhan, taking with him his
precious material, in order to fetch the necessary apparatus for his
researches. But during the long journey several eggs perished and he
had to return to the oasis with a borrowed microscope to study other
eggs on the spot. In spite of very difficult conditions and of the
persistent weakness of his eyesight, he succeeded in filling the lacuna
in the embryology of the _Geophilus_.

He had at the same time collected very interesting anthropological
data. His hypothesis as to the necessity of applying to anthropology
the comparative methods of embryology was fully justified, for, thanks
to that process, he was able to establish a definite correlation
between the Mongol race and the adolescence of the Caucasian race. He
presented a report on the subject to the Anthropological Society of
Moscow, but, his attention being afterwards turned in other directions,
he never came back to this subject.




                              CHAPTER XV

                                    "As to thee, Hector, thou art to
                                  me as a father and a revered mother
                                  and a brother, and thou art my
                                  husband."--_The Iliad._

  Studies on childhood--The family in the upper flat--Lessons in
  zoology--Second marriage--Private life--Visit and death of Lvovna
  Nevahovna--Conjugal affection.


Metchnikoff's anthropological researches led him to the study of
childhood, which in its turn suggested reflections on questions of
Pedagogy. His eyesight was still weak and his hunger for activity very
great; in order to satisfy it, he gave lessons in a Lycée and public
lectures in the Odessa University. Though time was passing, Metchnikoff
could not get used to his solitude; he spent his active kindness on his
friends and all around him, whilst living like an ascetic and giving
away all that he could spare. But nothing could quench his thirst for a
family life and affectionate intimacy.

My family at that time lived in the same house as he did, on the floor
above him; we were eight children, our ages ranging from one to sixteen
years. We were noisy neighbours and we incommoded Metchnikoff, who was
awakened every morning by the noise in our kitchen, where meat was
being minced for the children. One fine day he could stand it no longer
and went upstairs to ask if this nuisance could not be stopped; my
father promised that he would see that it ceased. We were all seated
round the tea-table when he came in, and, seeing a stranger, my sister
and I hurriedly collected our lesson books, and hastened to leave the
room. We did not even have time to distinguish Metchnikoff's features,
but were struck by his paleness. Shortly after that incident we met him
at the house of a mutual friend. He had already seen us from his window
as we went off to the Lycée, and it used to amuse him to see us bravely
stepping over a large pool of water which was permanent in the street.

One of his pupils was a professor in our Lycée, and Elie had the
opportunity of informing himself concerning our studies. Having heard
that I was interested in natural science, it occurred to him to offer
to give me lessons in zoology. I was delighted. He asked and obtained
permission from my parents, and we eagerly set to work. Elie, being
strongly attracted by me, returned to his former idea of training a
girl according to his own ideas and afterwards making her his wife. He
might have realised his programme of completing my education first and
marrying me afterwards if he had not been prevented by the complete
lack of accord between his ideas and those of my father. It was the
eternal conflict of two generations, "fathers and children." My father
was an excellent man, of great nobility of character, but he was a
type of the old Russian patrician school and belonged to a different
epoch, with different opinions and customs. This caused inevitable and
frequent disagreements, and Elie decided to ask for my hand without
further delay.

My mother was much younger than my father, and her sympathies
were all with the young generation. She was an idealist, gentle,
intelligent and artistic, and, in her youth, had painted and played the
violoncello, but a very early marriage and numerous children had forced
her to give up the practice of art, to her lifelong regret. Great
sympathy arose between her and Elie; she supported him in everything
and became for him a tenderly attached friend. He explained to her his
theories on marriage, and then confided to her his feelings towards
me. My extreme youth troubled her very much, but Elie endeavoured to
reassure her, saying that he fully understood the rashness of his
projects, but that he was ready to suffer all the consequences; in
fact, he declared, if he did not succeed in making me happy, he would
have the strength to help me to create another existence for myself. I
had not suspected my Professor's feelings towards me, and was deeply
moved when I was told of them; it seemed to me impossible to understand
that this superior, this learned man could wish to marry a little girl
like myself! I thought with terror that he must be mistaken about me;
I felt as if I were going up for an examination without any previous
study. However, I had a great affection and admiration for Elie; I was
attracted by his whole personality, which produced a strong impression
upon others as well as upon myself. This is how Setchénoff describes
him, in his own autobiography:

  Elie Metchnikoff was the soul of our circle. Of all the young men I
  have known in my life, young Metchnikoff was the most attractive with
  his lively intelligence, inexhaustible wit and abundant knowledge
  of all things. He was, in Science, as serious and as productive (he
  had already done much in zoology and acquired a great name in that
  branch) as he was full of life and varied interest in a circle of
  friends.

Moreover, my young imagination was impressed by his sad history and by
his interesting appearance, at that time not unlike a figure of Christ;
his pale face was illumined by the light in his kindly eyes, which at
times looked absolutely inspired. My whole heart went out to him, but I
was not yet ripe for matrimony and was somewhat thrown off my balance
by the unexpectedness of the event. Fearing that I was not up to his
level, I used to try beforehand to find worthy subjects of conversation
in order that he should not feel bored in my society, but everything
I thought of seemed to me so clumsy and stupid that I rejected one
subject after another until he came and found me at a loss. He could
not understand how deeply I was troubled, and cannot have been
satisfied with my attitude, which really was that of a zealous pupil.

Our marriage took place in February 1875; it was a very cold winter and
the ground was covered with a thick coating of glistening snow. A few
hours before the ceremony my brothers came with a little hand sledge
to fetch me for a last ride. "Come quick," they said, "this evening
you will be a grown-up lady, and you can't play with us any more!" I
agreed, and we rushed out to the snowy carpet which covered the great
yard of our house. In the midst of our mad race my mother appeared
at the window; she had been looking for me everywhere and was much
disturbed. "My dear child! what are you thinking of? It is late, you
have hardly time to dress and to do your hair!" "One more turn, mother!
It is the last time, think of it!" Other childish emotions awaited me;
my wedding-dress was the first long dress I had ever worn, and I feared
to stumble as I walked. Then, too, I was frightened at the idea of
entering the church under the eyes of all the guests. My little brother
tried to reassure me by offering to hold my hand, and my mother made me
drink some chocolate to give me courage.

Elie was awaiting us at the entrance; my shyness increased when I heard
people whispering around us, "Why, she is a mere child!" The ceremony
took place in the evening, after which Elie wrapped me carefully in
a long warm cloak and we set off, the sledge gliding like the wind,
towards our new home. In spite of the day's emotions, I rose very
early the next morning in order to work at my zoology exercises and to
give my husband a pleasant surprise. He was now free to superintend my
education, a very difficult and delicate task when having to do with a
mind as unprepared for life as mine was.

The scientific methods which Metchnikoff applied to everything might
have constituted a grave error at this delicate psychological moment;
yet, in many ways, he showed himself a strangely clear-sighted
educator. He made it a principle to give me entire liberty whilst
directing me through the logic of his arguments. It is with deep
gratitude that I realise how he, so superior to me, took care not to
stifle my fragile individuality but to respect it and to encourage
it to develop. Like all Russian young people of the time, I was very
enthusiastic concerning political and social questions that I was not
mature enough to understand, and my father forbade us to frequent
political circles with which he had no sympathy, fearing that we might
be influenced by them. Elie, on the contrary, left me full liberty,
though he himself disapproved of my tendencies. He considered that
political and social questions belonged to the realm of practical
experience, in which young people were lacking, as also in practical
preparation. He never prevented me from making myself acquainted with
the social movement, but submitted it to close analysis and criticism;
it is owing to this very efficacious method that I did not become one
of the numerous political victims of that time.

Elie took a lively and warm interest in everything which concerned
me. Not having had time to pass my final examinations from the Lycée
before my marriage, I was now obliged to go up before a special board
for the whole curriculum. He helped me to prepare this, even the
catechism, with the utmost keenness and gaiety, enlivening the driest
subjects by means of interesting and instructive reading. I was glad to
continue my biological studies under his direction after I had passed
my examinations. Not only did he give a general interest, a leading
thread, to every particular subject, but he also knew how to develop
independent work. For instance, he made me compare representative
examples of divers groups by practical study in order to let me deduce
for myself their characteristics and their generic connections.

And it was not my education only which interested him; he associated me
with every detail of his life and initiated me into his thoughts and
his work; we read together a great deal, he had an excellent delivery
and liked reading aloud.

He thoroughly enjoyed giving me pleasure; we often went to concerts
and theatres, and beautiful music or dramatic scenes moved him even to
tears. Musical themes haunted him, and he would whistle them softly
to himself even at his work. Without caring for luxury, he was glad
to contribute to the simple embellishment of our home because he knew
I appreciated it. When we travelled, always with scientific research
as an object, he never failed to point out every interesting feature
that we happened to pass. He had a peculiar talent for making a journey
instructive as well as attractive; his eagerness, infectious gaiety,
inquisitive mind, and remarkable organising faculty made of him an
incomparable guide and companion.

We worked together for many years; it was both delightful and
profitable to work with him, for he opened out his ideas unreservedly
and made one share his enthusiasm and his interest in investigations;
he could create an atmosphere of intimate union in the search for truth
which allowed the humblest worker to feel himself a collaborator in an
exalted task.

Though I always took a strong interest in scientific questions, Art
was the real passion of my life. But, imbued as I was with the narrow,
utilitarian views which surrounded my youth, I had looked upon Art as
a luxury which should not be indulged in at a time when the poorer
classes could not read and write. When at last I became emancipated
from this fallacy, my husband did his best to encourage my artistic
development though he himself did not appreciate plastic art. Form and
colour in themselves or in harmony did not appeal to him; he took much
more interest in a subject than in the way it was treated; he liked
psychological or realistic work, landscapes, "genre" pictures, but
classical, Renaissance, or Impressionist works bored him. In spite of
the divergence of our tastes in that connection, he never ceased to
encourage me or to take an active interest in my work; often and often
he accompanied me to picture galleries, making sincere and somewhat
pathetic efforts to appreciate the beauty of great masterpieces.

Next to music he enjoyed Nature most, perhaps because it offered him
an inexhaustible source of scientific observation. His wearied nerves
caused him to seek for soothing impressions, and calm, quiet ponds were
what he preferred, with their reeds and aquatic plants, among which he
loved to discover tiny beings, hidden under the leaves and below the
surface of the water.

Teaching and public work took up nearly the whole of his time;
his leisure was devoted to home life and to an intimate circle of
friends with whom he was bound by a common scientific fervour and by
a University life. He kept up those friendships even after life had
scattered them. His active kindness made him a centre of attraction
to his relations and we were always very much surrounded. After his
father died, in 1878, his mother and two of her grandchildren came to
live with us. She was at that time sixty-four years of age and had the
appearance of an old lady; she did not follow the fashion but wore her
white hair simply parted and framing her face; alone her fine dark
eyes had preserved their youthful sparkle and bore witness to her
former beauty. She had a bright and cheerful disposition and a charming
kindliness to every one; her desire for activity was unfortunately
thwarted by the state of her health.

Elie showed his mother a tender solicitude which manifested itself in
the smallest details; for instance, he who detested cards would play
Patience with her; or he would drive her round the markets, which
interested her like the good housekeeper she was. When he came in from
the laboratory he never failed to go to her to ask her for details
of her health; he talked to her playfully and affectionately, making
her laugh, telling her the incidents of the day. She continued to be
interested in everything, especially that which concerned her dear
Elie, the "consolation of her life," as she called him.

In spite of his affection for his mother, he bore her almost sudden
death very stoically, knowing as he did that the grave heart disease
from which she suffered was bound to cause her increasing pain.

My family became his, and the relations between him and my father
became such that the latter, feeling ill and nearing his end, made
him our guardian. Until the last my mother preserved for my husband
a tender friendship which he fully returned. For years he bore the
burden and responsibilities of the family. With my young brothers and
sisters he kept up a tone of merry affection; always indulgent with
them, he was anxious to neglect nothing that could be useful. Though
ever led by the desire to procure happiness around him, it sometimes
happened that he made a mistake in his appreciation and failed to
reach his goal. The human soul is a riddle, life is complicated, and
we ought not always to judge by results but by motives.... As far as I
am personally concerned, his affection, kindness, and solicitude have
always been unbounded. If during early years a few misunderstandings
arose between us, they were due to my youthful obstinacy or to his
nervous sensitiveness. We had our trials, but our friendship and deep
affection emerged from them stronger and purer than ever. At a certain
time, Elie, believing that happiness called me elsewhere, offered me
my liberty, urging that I had a moral right to it. The nobility of his
attitude was the best safeguard.... As years went on, our lives became
more and more united; we lived in deep communion of souls, for we had
reached that stage of mutual comprehension when darkness flees and all
is light.




                              CHAPTER XVI

  Metchnikoff at the age of thirty--Lecturing in Odessa University,
  from 1873 to 1882--Internal difficulties--Assassination of the Tsar,
  Alexander II.--Further troubles in the University--Resignation--Bad
  health: cardiac symptoms--Relapsing fever--Choroiditis--Studies
  on Ephemeridæ--Further studies on intracellular digestion--The
  _Parenchymella_--Holidays in the country--Experiments on agricultural
  pests.


Elie Metchnikoff was now thirty years old, and his personality was
fully characterised though it had not yet reached the culminating point
of its development.

His dominating point was his passionate vocation; his worship of
Science and of Reason made of him an inspired apostle. He had the
faults and qualities of a rich and powerful nature. Vibrating through
all the fibres of his being, he shed life and light around him. His
temper was violent and passionate; he could bear no attack on the ideas
which were dear to him, and became combative as soon as he thought them
threatened. His was a wrestler's temperament; obstacles exasperated
his energy and he went straight for them, pursuing his object with an
invincible tenacity; he never gave up a problem, however difficult, and
never hesitated to face any sacrifice or any privation if he thought
them necessary.

A strange contradiction with this iron will was offered by occasional
disconcerting impulses, like that which caused the failure of his
first journey abroad, or by sudden attacks of fury for insignificant
reasons such as an unexpected noise in the street, a cat mewing or a
dog barking, or angry impatience when he could not solve a frivolous
puzzle, etc. This impulsive disposition gradually calmed down as he
grew older, and ultimately very nearly disappeared.

In his personal relations also he was apt to lose his temper, but
a reaction very soon followed the outburst, and his efforts to be
forgiven when he felt guilty were very touching. On the other hand,
he did not easily forget an offence, though no desire for revenge
ever soiled his soul, and his gratitude for kindness was absolutely
indestructible.

He harboured pessimistic theories to that extent that he looked upon
the procreation of other lives as a crime on the part of a conscious
being; his physical and moral sensitiveness was intense. And yet he had
inherited from his mother a natural gaiety and delightful elasticity
which always ended by gaining the upper hand. He was fond of joking;
his wit was occasionally somewhat cutting, but that was entirely due
to the appropriateness of his remarks; he never hurt people's feelings
intentionally. He sometimes gave offence by a professional habit of
using personal and concrete instances by way of arguments, but he
applied the process to himself as well; it was the objective method,
nothing more, and those who knew him well never doubted it.

His benevolence was most active and never insipid, though marked by
an almost feminine sensibility. He was an incomparable companion and
friend, and had the gift of smoothing difficulties and inspiring
courage, security, and confidence. He took the greatest interest in
others and easily came down to their level, always finding points in
common, "an opportunity for the study of human documents," he said.
Thus he conversed simply and sympathetically with the humble as with
the great, with the young as with the old. It was no mere intellectual
interest that he bore them, but he put his whole heart into it, which
made him extremely easy to approach. And yet he never departed from
absolute freedom of speech, sometimes mixed with harshness. Truth and
sincerity, for him, came above everything; he carried the courage of
his opinions to the highest degree, even if it was likely to shock
his hearers or to do him harm. He jealously guarded his independence
and nothing could force him to act against his convictions. Full of
enthusiasm, always interesting, he enlivened all around him. His ideas
and his activity were in constant effervescence; no serious question
left him indifferent; he read everything, knew about almost everything,
and willingly informed others; his vibrating expansiveness made him a
centre of attraction in his private life as in the laboratory or in any
other sphere of activity.

From 1873 to 1882 his energies were chiefly absorbed by teaching and by
the inner life of the University of Odessa, into which he threw himself
with his usual enthusiasm. His lectures were full of life, always
bringing out general ideas to throw light upon the most arid facts; he
made use of these as an architect utilises coarse materials in order
to erect a harmonious edifice. His creative power endowed his lectures
with an æsthetic character in spite of their extreme simplicity; not
that he concerned himself much about form, but because of his wealth
of ideas and the logical way in which he developed them, starting from
the simple and reaching the complex in a harmonious synthesis. His own
enthusiasm established a living bond between him and his audience.

He was on excellent terms with the students, though he made no bid for
popularity. Not only did he give no encouragement to the prevailing
tendency of the young men towards politics, but he endeavoured on the
contrary to bring them back to their studies; he tried to prove to
them that social problems demand knowledge and a serious practical
preparation. Otherwise, said he, social life would be as medicine was
before it entered into the path of science, and when any middle-aged
woman, any bone-setter, was allowed to practise therapeutics. At the
same time, students found in him willing protection in the persecutions
directed against them, and earnest help in their work when they showed
the least interest in it; he would eagerly welcome the smallest spark
of the "sacred fire."

Owing to the absolute independence of his ideas and conduct he had
great influence on young men, and this caused him to be looked upon in
administrative spheres as a "Red"--almost an agitator. In reality he
was struggling against the inertia and reactionary forces which were
shackling the normal development of culture and science in Russia. He
called himself a "progressive evolutionist," for he considered that
alone a deep and conscious evolution could give stable results and lead
to real progress. He thought that Revolution, and especially Terrorism,
merely provoked a reaction which might be long-lived, and that, as
long as the people were not sufficiently educated, a revolution might
easily result in the transfer of despotism from one party to another.
Socialistic doctrines did not satisfy him; according to him, they
did not leave sufficient scope to personal initiative and to the
development of individuality, two factors which he considered as
essential to every progress.

He looked upon scientific work as his mission, and avoided politics
because he did not think himself competent to deal with them. But
scientific activity being closely limited by the state of the
University, which was badly oppressed at that time by reactionary
powers, he was led to take part in the defence of the University's
right to autonomy. He brought all his energies into the struggle,
though trying to keep from party tactics and to act purely in the
interests of science. For instance, he would vote either for a Radical
or a Conservative without sharing the opinions of either, but merely
guided by their scientific value.

At the beginning of his scientific career at Odessa he led a very
active campaign in favour of the teaching of Natural Science. He urged
that, in order to teach properly, Natural History professors should
themselves have made independent researches on living fauna and flora,
and tried to introduce a series of measures to allow biologists special
holidays and missions to desirable places, at the proper seasons, for
research purposes. "There is no doubt," he said, "that scientific
activity would be much increased if the proposed measures were adopted.
Then, before long, our young scientists would not need to go to
study in German universities, but could go abroad already prepared
to undertake independent research." The Commission which examined
his report demanded certain modifications, "because of the Imperial
injunction to be very strict in granting travelling permits to
professors." Metchnikoff somewhat altered the text, which, after being
adopted by the University Council, was rejected by the Ministry and
remained without effect. Thus was every independent suggestion stifled,
even when it had but a purely scientific object.

Soon the situation of the Odessa University became even more difficult.
Between 1875 and 1880 reaction increased considerably, and the inner
life of the University became very unfavourable to any scientific
activity. Already before that it was teeming with intrigues, the
Professors of Ukrainian origin being hostile to the "Muscovites." Yet
it was still possible to remain apart from these local intrigues, until
political reaction, filtering into the University, created in it the
deepest divisions. The hostility of parties was now based on political
opinions, either "Reactionary" or "Liberal." The students were being
more and more carried away by this movement and no longer took any
interest in their studies.

All these conditions made normal teaching and scientific work
impossible, and Metchnikoff, seeing that politics from above and
from below now swallowed up everything, tried to take refuge in
his laboratory but in vain; even there he could no longer find the
necessary calm, and only during the holidays could he really work.

Thus passed the years until March 1, 1881, when the crime which ended
the days of Alexander II. was followed by a great reactionary movement.
The authorities, seeing conspiracies and plots everywhere, persecuted
without cause all the elements which were ticketed as "dangerous."
Though the University still preserved its autonomy, this was entirely
fictitious, for the Ministry thwarted every desire for independence;
the nomination of professors elected by the University Council was only
ratified by the Ministry if they were reactionaries, without any regard
for their scientific value. Soon the Chairs were occupied by ignorant
men of doubtful morality.

The life and honour of the University became endangered, and
Metchnikoff found himself obliged to take part in the struggle; he did
so with vehemence and energy; the independence of the University was
involved, and, as long as he could hope to save it, he struggled. At
the meetings of the Council and of the Faculty he never failed to give
vent to his critical opinions with a vehement frankness which earned
him in the University the reputation of an "_enfant terrible_." In the
meanwhile every resolution passed by the Council, if not reactionary
in character, was systematically quashed by the Ministry, which thus
paralysed every means of action, and Metchnikoff found himself faced
with the alternative of submitting or handing in his resignation. He
decided for the latter: his convictions were involved, and moreover his
health could not withstand the continual agitation and strain on his
nerves.

As we could not afford to live in independence, he applied for a
vacant post of entomologist in the _zemstvo_[13] of Poltava, and at the
same time wrote out his resignation, holding it in readiness for an
opportunity which was not long in coming.

  [13] Rural administration.

The Conservative party in the Faculty arose against a Liberal professor
who had accepted a very clever thesis in which the Reactionaries
perceived Socialist tendencies. The Dean of the Faculty proposed that
all such theses should be refused, and the Faculty approved. This was
the signal for a storm in the University, the Dean was hooted by the
students, and many of them were threatened with being expelled. The
Curator desired the more influential professors, of whom Metchnikoff
was one, to intervene with the students in order to bring disorder to
an end, and the professors consented, on condition that the offending
Dean should resign. The Curator promised that he should be asked to do
so, and order was immediately restored; but the Dean remained and many
students were severely and unjustly punished. Metchnikoff thereupon
produced his resignation, which was promptly accepted, and thus his
University career came to an end.

Besides his University lectures, he gave public lectures on Natural
History which were attended by a number of female students, for women
at that time were only admitted to the Faculty of Medicine, and these
lectures were extremely useful to them. Metchnikoff, though he did
not believe that women could accomplish creative work in science,
was strongly in favour of higher education for women, considering
it as necessary to their general intellectual development. Genius,
he thought, was peculiar to the male sex, no woman having created
anything "of genius" even in domains which had always been accessible
to them, such as music, literature, and the applied arts. The very rare
exceptions, to his mind, only proved the rule; yet he did not draw the
conclusion that woman was in any sense inferior to man. He merely held
that her gifts are different from those of men.

       *       *       *       *       *

Metchnikoff's health had been seriously shaken by the emotions and
annoyances of university life. Already in 1877, after political
intrigues at the University, he had felt the first symptoms of cardiac
trouble, which were the beginning of a long period of ill-health. He
consulted Bamberger, a great Viennese physician, who, however, found
nothing serious, and merely forbade him the use of wine and tobacco, to
neither of which was he addicted.

His health suffered further through the violent anxiety which he went
through in 1880 whilst I lay dangerously ill with typhoid fever,
contracted in Naples. Though worn out with devoted nursing, he tried
to make up the time lost to research and over-worked himself, with
the result that cardiac trouble was followed by fits of giddiness and
unconquerable insomnia. He fell into such a state of neurasthenia that,
in 1881, he resolved in a moment of depression to do away with his life.

In order to spare his family the sorrow of an obvious suicide, he
inoculated himself with relapsing fever, choosing this disease in order
to ascertain at the same time whether it could be inoculated through
the blood. The answer was in the affirmative: he became very seriously
ill. His condition was aggravated by anxiety concerning the University;
for he was sufficiently conscious to be aware of the events which
were taking place in Russia. The murder of Alexander II. caused him
to foresee a political reaction of the most terrible type; already, a
reactionary Rector had been appointed. Metchnikoff developed intense
jaundice and had a serious relapse with alarming cardiac weakness;
during the crisis he had a very distinct prevision of approaching
death. This semi-conscious state was accompanied by a feeling of great
happiness; he imagined that he had solved all human ethical questions.
Much later, this fact led him to suppose that death could actually be
attended by agreeable sensations.

His robust nature, however, triumphed over all these grave
complications, and, during his convalescence, he was filled with a joy
of living such as he had never experienced before; from that moment
his moral and physical balance was completely restored. There was one
unpleasant sequel to his illness, an acute affection of the sight
(choroiditis), but it fortunately disappeared without leaving any
traces, and, in fact, he never suffered again from his eyes, in spite
of his constant use of the microscope.

After his recovery he had a renascence of vital intensity; the
life instinct developed in him in a high degree; his health became
flourishing, his energy and power for work greater than ever, and the
pessimism of his youth began to pale before the optimistic dawn of his
maturity. However, the relapsing fever had very probably increased, if
not started, the cardiac trouble which eventually caused his death.

During the time when Metchnikoff was forbidden the use of the
microscope on account of his eye weakness, he studied Ephemeridæ from
the point of view of natural selection. He wished to elucidate the
manner in which this selection operates during the very short life of
those insects: the rudimentary structure of their buccal organs does
not allow them to feed themselves, and they have no time to adapt
themselves to external conditions.

During the 1875 holidays, at Gmunden and on the Danube, he observed
the nuptial flight of the mayflies, a phenomenon which constitutes
their short adult existence, preceded by a long period in the larval
state. Thousands of these diaphanous, ephemeral insects swarm above
the water in a compact cloud; now and then, dead Ephemeridæ fall like
snow-flakes, and that is the final and tragic completion of the nuptial
flight. Metchnikoff wished to unveil the mechanism of this sudden
death, evidently due to a physiological cause; but he obtained no
definite results either that year or the following, when he continued
his observations in the Caucasus. He realised that the life of these
insects was too short to allow him to solve the problems which
interested him, and, his eyes now being cured, he went back to his
studies on the origin of multicellular beings or _metazoa_.

He studied the development of inferior sponges and ascertained that
they possess the three embryonic layers which correspond to those of
other animal types, but that these layers have not the same degree of
independence or differentiation. He found that in certain inferior
sponges the mesoderm develops before the endoderm and gives birth
to it. These two layers, born one from the other, manifest common
primordial characters. Therefore he was in no wise surprised to
discover that, in these inferior sponges, the amoeboid and mobile
cells of the mesoderm fulfil digestive functions equally with,
and even more than those of the endoderm; in fact, with primitive
beings, functional characters are not more strictly delimitated than
morphological characters. It is only a more advanced differentiation
which separates them.

He connected these new facts with that which he had observed in 1865
in one of the lower worms, the earth planarian _Geodesmus bilineatus_.
This worm is actually without a digestive cavity, for the latter is
entirely filled by parenchymatous cells inside which digestion takes
place.

By their primitive structure, lower sponges and worms come near the
higher Infusoria, to which they are even more closely related by this
intercellular digestion which is common to them.

This led Metchnikoff to ask himself whether this was not, generally
speaking, _the primitive mode of digestion_. He carried out numerous
researches on this point during the following years, and found the same
intercellular digestion in other lower worms, such as the _Mesostoma_
and aquatic planarians, and afterwards in some lower Coelentera and
some Echinoderma. He was thus enabled to establish definitely that the
primitive mode of digestion was really intercellular, for the lower
multicellular animals either do not possess any digestive cavity or
else their digestive cavity develops late, as for instance with lower
jelly-fish or with hydropolypi. Even when the cavity is developed in
these inferior animals, the digestive functions are fulfilled by the
mesodermic cells.

The question as to what are the ancestral forms of multicellular
animals cannot be solved through direct observation, for there is a
lacuna between them and unicellular beings, a lacuna which is due to
the disappearance of intermediary forms. It can only be filled by
hypotheses, based upon the embryology of those animals which, in their
embryonic development, repeat the inferior forms from which they are
derived, thus reflecting the general evolution of living beings. It
was therefore to the embryology of lower multicellular beings that
Metchnikoff turned, in order to endeavour to reconstitute their origin
and to show the link between them and unicellular beings.

We know that the _ovule_ or primitive genital cell of every animal
may be compared to a unicellular organism. After fertilisation the
egg undergoes consecutive divisions or segmentation; each segment
constitutes a new cell, and their aggregation forms a hollow sphere
called a _blastula_, which is similar to a colony of unicellular
beings. The blastula differentiates itself into embryonic layers, the
_ectoderm_, _endoderm_, and _mesoderm_ already mentioned.

In the majority of animals the origin of the first two layers, ectoderm
and endoderm, is due to the invagination of one of the poles of the
blastula; the invaginated part of the walls forms the internal layer,
the endoderm, and lines the cavity produced by invagination; this
cavity thus becomes a _digestive_ cavity. This stage of development,
called _gastrula_, is similar to a cup with a double wall, of which the
outer is the ectoderm and the inner the endoderm.

This stage, discovered by Kovalevsky, is to be found in the evolution
of most animals and corresponds to the adult stage of some of them. It
was consequently considered as the _primitive type_ of multicellular
beings.

Haeckel founded thereupon his theory of the _gastræa_, according
to which the common ancestor of animals was a lower animal, now
disappeared, and similar to that stage of development. He therefore
gave to this hypothetical animal the name of _gastræa_.

Metchnikoff, however, discovered among primitive multicellular animals,
such as sponges, hydroids, and lower medusæ, a stage of development
still more simple than the gastrula; this stage is without a
digestive cavity and only assumes the gastrula form in its ulterior
evolution. He also made the remarkable discovery that, in the most
primitive multicellular animals, the endoderm is formed, not by means
of invagination, but by the _migration_ of a number of flagellated
cells from one pole of the wall of the blastula into the central
cavity. These cells draw in their flagellum, become amoeboid and
mobile, multiply by division, fill the cavity of the blastula, and
become capable of digesting. They originate the digestive cells of
the complete organism and give birth to the mesoderm, which explains
how the latter comes to contain a number of devouring cells even
though these do not constitute digestive organs properly so called.
Metchnikoff gave to that stage the name of _parenchymella_, for
the migrating cells constitute the endoderm in the condition of a
parenchyma.

The invariable presence of this stage in the simplest multicellular
animals, the primitive amoeboid state of the endodermic cells,
cases of ulterior transformation of the parenchymella into the
gastrula form in certain animals, the absence of a differentiated
digestive cavity,--all that proved, according to Metchnikoff, that the
parenchymella is more primitive than the gastrula, and is therefore
entitled to be considered the prototype of multicellular beings.

He saw a confirmation of this in the fact that primitive adult animals
also have no digestive cavity but merely an intracellular digestion
(sponges, turbellaria).

He concluded that the common ancestor of multicellular beings was a
being constituted by an agglomeration of cells without a digestive
cavity, but endowed with intracellular digestion, like that of the
"parenchymula" stage of development. He therefore gave to that
hypothetical ancestor the name of _parenchymella_.

Later, in 1886, he definitely formulated his theory of the genesis of
multicellular beings, and having already stated the phagocyte theory,
he substituted for the name _parenchymella_ that of _phagocytella_,
which indicated at the same time the primitive mode of digestion of
that hypothetical ancestor.

Reduced to its simplest form, it presented, according to Metchnikoff,
a certain analogy with a colony composed of unicellular beings of two
kinds: the first, flagellated, forming the external layer, and the
others, amoeboid, occupying the centre of the colony and capable of
digesting.

It may be interesting to mention here that, in this hypothetical
description, Metchnikoff foresaw the existence of similar, but real,
beings discovered a year later by Saville Kent, namely, the flagellated
colonies of _Protospongia_.

Thus the link between the unicellular and the multicellular beings
could be constituted through the intermediary of flagellated colonies
on the one hand and, on the other hand, of beings similar to a
_phagocytella_. The _indivisible colony_ became the _multicellular
individual_.

While studying the genealogy of beings, Metchnikoff continued his
researches on intracellular digestion. In 1879, at Naples and at
Messina, he was able to establish the fact that the mesodermic cells
of many larvæ of Echinodermata and Coelenterata, endowed with a
digestive tube, nevertheless contained strange bodies. Therefore, even
complicated organisms with a differentiated digestive system could
still contain at the same time some primitive cells with an autonomous
digestion.

All these researches on the unity of the origin of multicellular
beings and their morphological elements, and also those concerning
intracellular digestion, were gradually preparing Metchnikoff's mind
for the conception of the phagocyte theory.

       *       *       *       *       *

We spent the summer of 1880 with my family in the country. The cereals
were invaded by a harmful beetle, the _Anisoplia austriaca_, which was
devastating the country. Metchnikoff took the study of this scourge to
heart and tried to find a remedy. He had, the preceding year, observed
a dead fly enveloped with a sort of fungus which had evidently been
the cause of its death. Hence he conceived the idea that it might be
possible to combat harmful insects by provoking epidemics among them.
He now returned to this idea; on dead bodies of _Anisoplia_ he found a
small fungus, the _muscardine_, which was invading the insects by means
of filaments, and he succeeded in infecting healthy beetles.

At first he confined himself to laboratory experiments; then a great
landowner, Count Bobrinsky, placed experimental fields at his disposal.
As the acquired results were very encouraging, Metchnikoff, forced
to leave the neighbourhood, left a young entomologist in charge of
the application of his method. So far as he himself was concerned,
this study proved the starting-point of his researches on infectious
diseases.




                             CHAPTER XVII

  Death of his father- and mother-in-law--Management of country
  estates--Agitation and difficulties--Departure for Messina with
  young brothers- and sisters-in-law.


In the spring of 1881, Metchnikoff having recovered from relapsing
fever, we went to stay with my parents at Kieff and found my father
dying. He entrusted Elie with the care of the family, and they came to
live with us at Odessa. But, the following year, we had the misfortune
to lose my mother also. From that moment my husband took upon himself
the responsibility of the whole family.

Our resources came from landed property, and he, who had never
concerned himself with rural questions, had to make himself acquainted
with them. In this he was greatly helped by a neighbour, Count
Bobrinsky, through whose influence he came to abandon the purely
theoretical opinions he had hitherto held concerning agrarian
questions. He had considered communal property as a desirable agrarian
system: Count Bobrinsky showed him that it was not so, at any rate in
Little Russia.

Metchnikoff came to the country with the keenest desire to make himself
useful. First of all he devoted the gratuity which he had received on
leaving the University, to a school which my sister and myself desired
to open in our family property. But we were met by administrative
opposition which nearly wrecked our plan, under the pretext that it was
intended for political propaganda. And though cordial relations were
established from the first between Metchnikoff and the peasantry, many
complications were unavoidable, due to the general agrarian situation,
to the insufficiency of the peasants' allotments, and to their
primitive methods of cultivation.

My father, whose property was in the province of Kieff, had inherited
another domain in that of Kherson; Metchnikoff therefore had to
manage both estates and to adapt himself to their very different
respective circumstances. The majority of the farmers in Little Russia
at that time were Jews and were beginning to be persecuted both by
the Government and by the peasants; Elie was constantly obliged to
intervene. In the province of Kherson, it was a tradition with the
peasants that the land should belong to them, and they imagined that
this could be brought about by the simple elimination of the farmers.
Therefore they inflicted constant vexations upon the latter, allowing
cattle to pasture in their crops, pulling up their beetroots, etc.
Metchnikoff attempted in vain to re-establish peace by means of
compromise; he persuaded a farmer to sub-let part of the land to the
peasants, but this had to be given up, for the latter did not carry out
their engagements. Relations between the farmers and the peasants were
getting worse and worse, and Metchnikoff, foreseeing a catastrophe,
warned the local administration that the situation was getting very
grave and would lead to irreparable consequences. He was merely told
that preventive measures would be useless; hereupon the peasants
brutally murdered a keeper who was turning the cattle away from the
crops. Then at last the administration awoke, arrested the murderers,
and twelve men were exiled to Siberia.

All this caused Metchnikoff the deepest anxiety, the more so that he
was absolutely incapable of altering the situation. As soon as it
became possible, he sold to the peasants that portion of the land
which belonged to us personally; until then, the property had been
common to the whole family, of which the younger members were not yet
of age. This, however, was not a general solution, and these moral
preoccupations, as well as the heavy responsibility incumbent upon him,
kept him from his scientific work. He was therefore very pleased to
hand over the management of the property to one of my brothers who had
just completed his studies in a Higher Agricultural School, and, in
spite of difficult conditions, Elie had the satisfaction of giving up
everything in good order.

Thanks to my parents' inheritance, he was able to abandon his share of
the Panassovka patrimony to the children of his brother and to live
henceforth independently. He wished to pursue researches on the shores
of the Mediterranean: therefore, in the autumn of the year 1882, we
went to Messina with my two sisters and my three young brothers. The
children were no trouble to Elie, who loved them; on the contrary, he
enjoyed organising the journey and arranging all sorts of pleasures for
them. The children, accustomed to his kindly indulgence, always came to
"the Prophet" for everything they wanted.[14]

  [14] "Elie" is the French form of Elijah, in Russian Ilia, and
       was ultimately adopted by Metchnikoff.




                             CHAPTER XVIII

  Messina--Inception of the phagocyte theory--Encouragement from
  Virchow and Kleinenberg--First paper on phagocytosis at the Odessa
  Congress in 1883--The question of Immunity--Article in Virchow's
  _Archiv_, 1884.


At Messina, we settled in a suburb, the Ringo, on the quay of the
Straits, in a small flat with a garden and a splendid view over the
sea. We did not have much room, and the laboratory had to be installed
in the drawing-room, but, on the other hand, Elie only had to cross the
quay in order to find the fisherman who provided him with the material
needed for his researches and with whom we frequently went sailing.

Metchnikoff loved Messina, with its rich marine fauna and beautiful
scenery. The splendid view of the sea and the calm outline of the
Calabrian coast across the Straits delighted him. He enjoyed it all
the more after the many excitements of life at the University, and
eagerly gave himself up to his researches. Often, in later years, he
delighted to recall memories of that period, the more so that this was
connected with the principal phase of scientific activity which led to
the formation of his phagocyte theory. After the earthquake in 1908,
he wrote a few pages on Messina and ended his article by the following
lines:

  Thus it was in Messina that the great event of my scientific life
  took place. A zoologist until then, I suddenly became a pathologist.
  I entered into a new road in which my later activity was to be
  exerted.

  It is with warm feeling that I evoke that distant past and with
  tenderness that I think of Messina, of which the terrible fate has
  deeply moved my heart.

  They say that Messina will be rebuilt in the same place but in a
  different way. Houses will be constructed of light materials, they
  will be low, and the streets broad....

  The town will be a new Messina, not "my Messina," not that with which
  so many dear memories are associated in my mind....

Metchnikoff continued to study intracellular digestion and the origin
of the intestine. He foresaw that the solution of those problems
would lead to general results of great importance. The study of
medusæ and of their mesodermic digestion confirmed him more and more
in the conviction that the mesoderm was a vestige of elements with a
primitive _digestive_ function. In lower beings, such as sponges, this
function takes place without being differentiated, whilst with other
Coelentera and with some Echinoderma the _endoderm_ gives birth to
a digestive cavity; yet, the mobile cells of the _mesoderm_ preserve
their faculty of intracellular digestion. As he studied these phenomena
more closely, he ascertained that mesodermic cells accumulated around
grains of carmine introduced into the organism.

All this prepared the ground for the phagocyte theory, of which he
himself described the inception in the following words:

  I was resting from the shock of the events which provoked my
  resignation from the University and indulging enthusiastically in
  researches in the splendid setting of the Straits of Messina.

  One day when the whole family had gone to a circus to see some
  extraordinary performing apes, I remained alone with my microscope,
  observing the life in the mobile cells of a transparent star-fish
  larva, when a new thought suddenly flashed across my brain. It struck
  me that similar cells might serve in the defence of the organism
  against intruders. Feeling that there was in this something of
  surpassing interest, I felt so excited that I began striding up and
  down the room and even went to the seashore in order to collect my
  thoughts.

  I said to myself that, if my supposition was true, a splinter
  introduced into the body of a star-fish larva, devoid of
  blood-vessels or of a nervous system, should soon be surrounded by
  mobile cells as is to be observed in a man who runs a splinter into
  his finger. This was no sooner said than done.

  There was a small garden to our dwelling, in which we had a few days
  previously organised a "Christmas tree" for the children on a little
  tangerine tree; I fetched from it a few rose thorns and introduced
  them at once under the skin of some beautiful star-fish larvæ as
  transparent as water.

  I was too excited to sleep that night in the expectation of
  the result of my experiment, and very early the next morning I
  ascertained that it had fully succeeded.

  That experiment formed the basis of the phagocyte theory, to the
  development of which I devoted the next twenty-five years of my life.

This very simple experiment struck Metchnikoff by its intimate
similarity with the phenomenon which takes place in the formation of
pus, the diapedesis[15] of inflammation in man and the higher animals.
The white blood corpuscles, or _leucocytes_, which constitute pus, are
mobile mesodermic cells. But, while with higher animals the phenomenon
is complicated by the existence of blood-vessels and a nervous system,
in a star-fish larva, devoid of those organs, the same phenomenon is
reduced to the accumulation of mobile cells around the splinter. This
proves that the essence of inflammation consists in the reaction of
the mobile cells, whilst vascular and nervous intervention has but a
secondary significance. Therefore, if the phenomenon is considered in
its simplest expression, inflammation is merely _a reaction of the
mesodermic cells against an external agent_.

  [15] Migration of the white blood corpuscles (leucocytes) through
       the walls of blood-vessels.

Metchnikoff then reasoned as follows: In man, microbes are usually
the cause which provokes inflammation; therefore it is against those
intruders that the mobile mesodermic cells have to strive. These mobile
cells must destroy the microbes by digesting them and thus bring about
a cure.

Inflammation is thus a _curative reaction_ of the organism, and morbid
symptoms are no other than the signs of the struggle between the
mesodermic cells and the microbes.

In order to verify these conjectures, he started studying the
englobing of microbes by mesodermic cells in larvæ and in other marine
invertebrates which he inoculated.

At that time, a well-known German scientist, Kleinenberg, was Professor
of Zoology at Messina. Metchnikoff imparted his ideas to him and showed
him his experiments. Kleinenberg encouraged him very much; he looked
upon his theory as "an Hippocratic thought" and advised him to publish
it at once.

Metchnikoff was also greatly encouraged by Virchow, who happened
to pass through Messina and came to see his preparations and his
experiments, which seemed to him conclusive. However, Virchow advised
him to proceed with the greatest prudence in their interpretation, as,
he said, the theory of inflammation admitted in contemporary medicine
was exactly contrary to Metchnikoff's. It was believed that the
leucocytes, far from destroying microbes, spread them by carrying them
and by forming a medium favourable to their growth.

Metchnikoff always preserved a deep gratitude towards Virchow and
Kleinenberg for the moral support which they gave him at that time.

       *       *       *       *       *

When the hot weather came, we left Messina for Riva, a delicious summer
resort on the shores of the Lake of Garda. There, Metchnikoff wrote
his first memoir on the reaction of inflammation and on the digestion
of microbes by the mesodermic cells of lower invertebrates. On the way
back to Russia through Vienna, he went to see the Professor of Zoology,
Claus; he found other colleagues with him and expounded his theory
to them. They were much interested, and he asked them for a Greek
translation of the words "devouring cells," and that is how they were
given the name of _phagocytes_.

Claus asked him for his memoir for the Review which he edited and in
which it appeared soon afterwards, in 1883.[16] The new-born "phagocyte
theory" was thus very well received by naturalists and by Virchow, the
father of cellular pathology.

  [16] _Arbeiten des zool. Inst. zu Wien_, Bd. v. Heft ii. p.
       141. "Untersuchung über die intracelluläre Verdauung bei
       wirbellosen Tieren," E. Metchnikoff.

Having returned to Russia, we went to the country, where Elie had to
attend to family business; nevertheless, he continued his researches
in every leisure moment. He had observed in Echinoderma that, during
the transformation of their larvæ, the parts becoming atrophied were
englobed by mesodermic mobile cells. In those observations he was
delighted to have found an example of _physiological inflammation_,
_i.e._ one which presented itself in normal and non-morbid conditions.
He thought he might observe it also during the metamorphosis of the
tadpole into a frog, whilst the tail was being atrophied. But he found
that, instead of the leucocytes of the blood, certain cells from the
muscular tissue were those which devoured the enfeebled elements of the
tail; he thus learnt that phagocytes might be, not only the white blood
corpuscles, but other cells of mesodermic origin.[17]

  [17] It was only in 1892 that he completed and developed his
       observations. He found that the cells of the sarcoplasma
       of the muscular tissue devoured its contractile part, the
       myoplasma.

In autumn 1883 he read his first paper on phagocytosis to a congress of
physicians and naturalists at Odessa.[18] He compared the phagocytes to
an army hurling itself upon the enemy and looked upon the phagocytic
reaction as a defensive force of the organism.

  [18] This paper was entitled "Forces curatives de l'organisme."

In that paper itself and from that moment onwards, the trend of his
ideas towards optimism becomes visible. By discovering the phagocytic
reaction of the organism, he made a first breach in his philosophy
of human nature, hitherto so pessimistic; he discovered within it a
salutary element which could be utilised by science to combat its
discords. He began to have some faith in the power of knowledge, not
only for this struggle, but also for the establishment of a rational
conception of life in general. Thus he said in his paper to the Odessa
Congress:

  The theoretical study of Natural History problems (in the largest
  sense of the word) alone can provide a critical method for the
  comprehension of truth and lead to a definite conception of life, or
  at least allow us to approach one.

And yet, until then, the theory of phagocytosis as a curative force
of the organism was but a hypothesis, for he had not yet observed
_spontaneous phagocytosis in diseases_ and did not know pathogenic
microbes. He therefore sought to study them in lower animals, whose
simple structure made the observation easier. He found some small,
transparent, fresh-water crustaceans, called _daphniæ_, which were
diseased and easy to place alive under a microscope. These crustaceans
are often infected by a parasite fungus (_Monospora bicuspidata_), of
which the spores, shaped like sharp needles, are introduced with food
into the digestive tube, traverse the walls of it, and thus penetrate
into the general cavity of the body. They are immediately attacked by
mobile phagocytes, which either singly or in groups englobe them; if
the phagocytes succeed in digesting the spores, the daphnia recovers;
in the contrary case, the spores germinate and develop into small
fungi which invade the organism and kill it. The recovery or death of
the daphnia depends therefore on the issue of the struggle.[19] This
observation gave final confirmation to the hypothesis of the curative
forces of the organism.

  [19] Virchow's _Archiv_, vol. 96, p. 177.

Metchnikoff was not content with observing lower animals but wished to
study the reaction of the organism of mammals in infectious diseases.
At that time, the best-known microbe was the bacillus of anthrax.
He therefore chose that for his researches and ascertained that
phagocytosis varied with the virulence of the microbes; thus, while
phagocytes did not attack virulent bacteria, they attacked and rapidly
digested attenuated bacteria. Moreover, he observed a very active
phagocytosis in refractory animals and the reverse in sensitive ones.

He thus came face to face with the question of _immunity_.

He approached it by a comparative examination of the reaction of
the organism of vaccinated rabbits and of non-vaccinated ones, and
ascertained that an active phagocytosis was only manifested in a
previously vaccinated organism. Metchnikoff explained these facts by
the theory that the phagocytes became accustomed, gradually, through
vaccination, to strive against more and more virulent microbes.

From that moment, immunity appeared to him as being no other than this
progressive hardening. He published his researches in 1884 in Virchow's
_Archiv_, and impatiently awaited medical reviews, hoping to find some
answer, but the memoir passed unnoticed; the full significance of it
had not been grasped.




                              CHAPTER XIX

  Ill-health of his wife and sister-in-law--Journey to Tangiers through
  Spain--Villefranche--Baumgarten criticises the phagocyte theory.


In 1884, Metchnikoff's work was interrupted by the ill-health of my
eldest sister and of myself; physicians considered that we had weak
lungs and advised that we should spend the winter in the South. Elie,
full of anxiety, hastened to take us there.

My younger brothers were now old enough to remain at school in our
absence so as to go on with their studies; we therefore started with my
two sisters. As cholera was raging in Italy, we went to Spain, hoping
to find a place with a mild climate and conditions favourable to my
husband's work. But we traversed the whole country without finding
the right combination, and, as we had come too far to go back, we
decided to spend the winter on the African coast, at Tangiers, close to
Gibraltar where we were.

Metchnikoff had not much taste for sight-seeing, but, with his
inquisitive and observing mind, liked to understand what he saw, and
never failed to acquaint himself with the history of the countries
which we traversed and which, with his ever-ready solicitude, he
wanted us to see. We therefore saw every interesting town on our route
through Spain. In the evenings we read together works on the history
and art of the country, and in the day-time we went for long rambles
in order to examine all that there was to see. The history of the
country, full of the sombre fanaticism which is reflected in its art,
the austere aridity of the central plateau of the land, the reserved
temper of the population--none of that found any echo in the vibrating,
sunlight-loving soul of Metchnikoff.

Gentle Italy, her exuberant life and highly-cultured past, charmed him
much more. He was consequently better pleased with Southern Spain,
which is more similar to Italy. He was greatly impressed by the
grandiose site and luminous atmosphere of Granada and the Alhambra and
by the superb gardens of Malaga, with their tropical plants and avenues
of palm trees.

At Gibraltar, he was greatly interested as a zoologist in the only
monkeys (_Macaques_ or Barbary apes) which have remained wild in
Europe; he never tired of watching their habits whilst those amusing
creatures jumped from tree to tree above our heads.

He had ample leisure to do so, for a frightful tempest kept us at
Gibraltar, preventing the crossing of the Straits. As Metchnikoff was
very anxious to set to work, we took the first steamship which ventured
out, but the sea was still running so high that our ship was damaged
and we had to go back. A panic took possession of the passengers,
during which my sisters and I were struck by the calmness of Elie, who
did not seem to realise the danger. After a delay of a few days, we
were at last able to cross.

Our first impression of Tangiers, an Arab port of a thoroughly Oriental
type, was extremely vivid. The city lay before us with its tall
minarets and flat roofs, shining white under the burning sun. The
steamer dropped anchor some distance from the landing stage, and we
were taken ashore on small boats, immediately to be surrounded by a
motley crowd with faces varying from the pale olive of the pure Arab
to the coal-black of the negro. All these people, in brilliant and
picturesque garments, were shouting, gesticulating, fighting for the
possession of passengers and their luggage, dragging them into the
boats or carrying them on their backs, themselves standing up to their
waists in water.

That feverish agitation, noise, and glaring sunlight introduced us
suddenly to new and violent sensations.

Already at Gibraltar, Metchnikoff had made arrangements with a
Spanish-speaking Arab from Tangiers who undertook our installation.
He provided us with a very primitive dwelling, himself serving as our
guide, cook, and general factotum.

We hastened to look for zoological material: alas, the sea was almost
a desert. After a long search we only found a few rare sea-urchins,
and Metchnikoff had to content himself with this meagre fauna during
the whole of the winter. He resigned himself to the study of the
embryology of sea-urchins in order to fill a few lacunæ in his previous
researches. As he could not work much for lack of materials, he
came with us for long excursions, during which he used to improvise
interminable and very amusing tales with which to entertain my little
sister.

At the beginning of our stay we were greatly interested by the life and
customs of the country. The picturesque and varied crowd, the dignified
and biblical types of Arabs, the bronzed Berbers, negroes, fanatical
sects of Aïssawas, snake-charmers, the jousts, and mad races of
cavalry across the sandy beach; opium smokers; mysterious silhouettes
of veiled women; the call to prayer from the tall minarets--all
that strange and exotic life fascinated us. But after a time the
wild customs, continual shouting on the occasion of every ceremony,
vendettas, cruel fanaticism, and also the absolute lack of intellectual
resources, began to tell on our nerves. Inactivity weighed heavily upon
Metchnikoff; nevertheless, he bore his ill-luck with his usual courage
and gaiety, finding great consolation in the excellent influence that
the climate of Tangiers had upon all our healths.

At last, in the spring, we started for Villefranche, where he
immediately set to work with success upon the embryology of jelly-fish;
an important monograph on that subject was published by him in 1886.
In it he gave definite form to his theory of the _phagocytella_ and
the genetic relationships of animals and of their primitive organs, a
theory already mentioned above (p. 110).

From Villefranche we went to Trieste, where Metchnikoff studied
star-fish and filled the lacunæ in his researches on the origin of the
mesoderm.

In a medical review which he read at Trieste, he found the first
account of his phagocyte theory; it was an unfavourable and hostile
criticism by a German scientist of the name of Baumgarten, endeavouring
to prove that Metchnikoff's deductions were inadmissible. This grieved
and pained him very much, but he immediately recovered himself and
strongly determined to study the medical side of the question in order
to prove on that ground that his theory was well-founded.




                              CHAPTER XX

  A Bacteriological Institute in Odessa--Unsatisfactory conditions--
  Experiments on erysipelas and on relapsing fever.


The results of Pasteur's antirabic inoculations were published in 1885.
The Municipality of Odessa, desirous of founding a bacteriological
station in that town, sent Dr. Gamaléia to Paris to study the new
method. Metchnikoff was appointed Scientific Director of the new
institution, and Drs. Gamaléia and Bardach, former pupils of his, were
entrusted with the preparation of vaccines and preventive inoculations.
The Institute, opened in 1886, was founded at the expense of the
Municipality of Odessa and of the _Zemstvo_ of the Kherson Province.

Metchnikoff himself describes as follows the short time he spent in
that Institute:

  ... Having given up my State work, I placed myself at the service of
  the city and the _Zemstvo_.

  Absorbed as I was by the scientific part of the work, I confided to
  my young colleagues the practical part, i.e. the vaccinations and the
  perfection of vaccines.

  It was to be supposed that all would go very well.

  Work in the new Institute began with ardour. But, very soon, a strong
  opposition manifested itself against it.

  The medical administration began to make incursions into the
  Institute, with a view to finding some infractions of the regulations.

  Medical society was hostile to every work which issued from the
  laboratory. The institutions which had subscribed funds for the
  Institute were demanding practical results, while all necessary work
  towards that object was met by every sort of obstacle.

  For instance, in order to destroy certain voles, very harmful to
  the cereals of Southern Russia, we proposed to make experiments as
  to infecting those rodents with the microbe of chicken cholera.
  Laboratory experiments were begun with that object. But, one day,
  I received an order from the Prefect peremptorily forbidding those
  experiments. This measure had been taken at the instigation of local
  physicians; having seen in a Petersburg newspaper an article by
  some one who had not a notion of bacteriology, they had assured the
  Prefect that chicken cholera could turn into Asiatic cholera.

  I had to appeal to the General Governor, who ended by countermanding
  the Prefect's order; nevertheless this incident was not without
  regrettable consequences concerning the ulterior activities of the
  Institute.

  Apart from all that, a deep scission took place between the members,
  though they were so few, of the Institute itself, and this had fatal
  consequences.

  The men who were in charge of the practical work ceased to work
  in concert; I could not take their place, being overwhelmed with
  scientific researches, besides which, holding no medical degree, I
  was not qualified to perform vaccinations on human beings.

  Under those conditions, I understood that in my quality as a
  theoretician, I should do well to retire, leaving the laboratory to
  practitioners who, bearing full responsibility, would fill the part
  better.

During his stay at the Odessa Bacteriological Institute, Metchnikoff
had busied himself with infectious diseases in order to answer the
first objections to his theory. He began by the microbes of erysipelas
and showed that the phenomena of the disease, as well as those of
recovery, were in full accord with the postulates of the phagocyte
theory.

And then he studied relapsing fever in order to answer Baumgarten's
objections, affirming that there was no phagocytic reaction in that
disease, though it almost invariably ended in recovery. Experiments
on man not being possible, Metchnikoff procured some monkeys, which
he inoculated with relapsing fever, and ascertained that Baumgarten's
error was due to the fact that he had only looked for phagocytosis in
the patient's blood, whilst it really took place in the spleen.

These researches on erysipelas and relapsing fever were published in
Virchow's _Archives_ in 1887. Besides this scientific work, he was also
giving lectures on bacteriology to some physicians, and was in full
productive activity when external opposition and the discord among his
collaborators in the Institute itself forced upon him the conviction
that he could remain there no longer.

At that very moment the Prince of Oldenburg, having founded a
Bacteriological Institute at Petersburg, invited Metchnikoff to take
charge of it. He had to refuse, fearing the Northern climate for my
health, and knowing from experience that it was impossible for a layman
to manage an Institute with a medical staff. Yet he could not do
without a laboratory. Seeing no possibility of having one in Russia, he
decided to look abroad for a refuge and a laboratory.

"Having learnt from experience at Odessa," he wrote, "how difficult was
the struggle against an opposition coming from all sides and devoid
of reasonable causes, I preferred to go abroad to look for a peaceful
shelter for my scientific researches."

We were no longer held back by family considerations; our links with
Russia had gradually loosened. He had resigned from the University,
discord reigned at the Odessa Bacteriological Institute, conditions
of life in Russia were very unfavourable to scientific activity; in
a word, "obstacles from above, from below, and from all sides,"--as
Metchnikoff expressed it,--gradually led to his resolution to leave his
native country.




                              CHAPTER XXI

  Hygiene Congress in Vienna--Wiesbaden--Munich--Paris and
  Pasteur--Berlin and Koch--Failure of anthrax vaccination
  of sheep--Decision to leave Russia.


In 1887 we went to Vienna, where a Congress of Hygienists was held,
in which, for the first time, bacteriologists took part. Metchnikoff
thus had the opportunity of becoming acquainted with many of them and
to make inquiries concerning bacteriological laboratories. Professor
Hueppe, of Wiesbaden, very kindly invited him to come to work in his
own. The idea pleased Metchnikoff, who thought that a peaceful little
University town would be very favourable to his work. But he found
that his situation would be very difficult at Wiesbaden on account of
the lack of harmony between the different laboratories in the town; he
therefore gave up the project which had seemed to him so tempting.

By this time many objections had been raised against the phagocyte
theory, and, Emmerich having attacked him very violently, Metchnikoff
went to Munich to have an explanation with him. This gave him the
opportunity of realising that Munich, like Wiesbaden, was not a place
where he would care to settle.

He had a great desire to know Pasteur and his collaborators, who had
just been playing such an important scientific part, and, finding
ourselves within easy reach of Paris, we repaired thither, without
the slightest idea of settling there. This is how Metchnikoff himself
described his first interview with Pasteur:

  On arriving at the laboratory destined for the antirabic
  vaccinations, I saw an old man, rather undersized, with a left
  hemiplegia, very piercing grey eyes, a short beard and moustache and
  slightly grey hair, covered by a black skull-cap. His pale and sickly
  complexion and tired look betokened a man who was not likely to live
  many more years. He received me very kindly, and immediately spoke
  to me of the question which interested me most, the struggle of the
  organism against microbes.

  "I at once placed myself on your side," he told me, "for I have
  for many years been struck by the struggle between the divers
  micro-organisms which I have had occasion to observe. I believe you
  are on the right road."

Pasteur at that time was chiefly occupied with antirabic vaccinations
and with the building of a new Institute in the rue Dutot. Seeing the
vast dimensions of the edifice and learning that the scientific staff
was not large, Metchnikoff asked Pasteur if he might hope to work in
one of the laboratories in an honorary capacity. Pasteur not only
acceded to this request but offered him a whole laboratory. He was
most kind, invited us to his home and introduced Metchnikoff to his
collaborators, who produced an excellent impression on my husband.

Though all this made him incline more and more towards the Pasteur
Institute, he still dreaded life in a large and noisy city, thinking
that a peaceful little University town would be more favourable to his
work. Therefore, before making a final decision, he desired to visit a
few more bacteriological laboratories.

On our way back we passed through Berlin, where Metchnikoff wished
to see Professor Koch and to show him some interesting specimens of
phagocytosis. The great _savant_ received him very coldly. For a long
time, while examining specimens of the spleen in relapsing fever, he
refused to recognise in them an example of phagocytosis. Though he
was at last obliged to bow to evidence, he yet remained unfavourable
to the phagocyte theory, and all his assistants followed his example.
Metchnikoff was much surprised and grieved by this hostility towards
his ideas, notwithstanding that they were based on well-established
facts. We hastened to leave Berlin.

Many years later, when phagocytosis was generally admitted, even in
Germany, Professor Koch and many other German scientists welcomed
Metchnikoff very kindly, which somewhat counterbalanced the
unpleasantness of early memories. But, at that time, the contrast
between our impression of Paris and of Germany was so great that all
hesitation was at an end: the choice was made.

On returning to Odessa, Metchnikoff began to prepare his resignation
and his departure. Yet he still had time to make some researches on
phagocytosis in tuberculosis, in reply to the objections which rained
upon his theory.

In the spring, he handed over the direction of the Institute to Dr.
Gamaléia and took leave; we went to the country for a while before
our final departure. During that time, Drs. Gamaléia and Bardach were
making anthrax vaccinations on a large scale in a vast private property
in the province of Kherson. When we were settled in our country
home, Metchnikoff received a telegram announcing that the first
anthrax vaccine had killed many thousand sheep. Though, as a matter
of fact, his personal responsibility was not involved, the blow was a
terrible one; he hastened back to Odessa to elucidate the cause of the
catastrophe. But it remained obscure....

This painful episode was the last drop which made the cup brim over; it
strengthened Metchnikoff in his resolve to leave Russia.




                             CHAPTER XXII

  The Pasteur Institute--Dreams realised--Metchnikoff at fifty--
  Growing optimism--Attenuated sensitiveness--The Sèvres villa--
  Daily routine.


Having decided to settle in France, we hastened to make ourselves
acquainted with contemporary French literature, thinking to find in it
a reflection of the soul and manners of the nation. But the realistic
literature of the time, in spite of the great artistic worth of many of
the authors, gave us an erroneous idea of life in France, of which it
represented but one of many aspects. It was therefore with apprehension
that we asked ourselves if we should ever be able to adapt ourselves to
the new conditions, and whether our isolation would not be great.

We arrived in Paris on the 15th of October 1888, and we lodged at a
small hotel in the Latin quarter, not far from the rue d'Ulm where the
old Pasteur Institute stood, the new one not being completed. There
was but little room in the laboratory, and Metchnikoff felt rather
uneasy, fearing that he was in the way. But the new Institute soon was
sufficiently advanced for him to settle there.

He was given two rooms on the second floor; I served as his assistant;
he was perfectly happy at being at last able to give himself up in
peace to his work. Soon, young physicians came to work under his
direction. Their number having increased, he was given a whole floor in
which to instal them, two rooms on that floor being reserved for his
own use. He occupied these rooms until the end of his life.

His dreams were at last realised. This is from a narration of the
causes which led to his departure from Russia, in his own words:

  Thus it was in Paris that I succeeded at last in practising pure
  Science apart from all politics or any public function. That dream
  could not have been realised in Russia because of obstacles from
  above, from below, and from all sides. One might think that the hour
  of science in Russia has not yet struck. I do not believe that. I
  think, on the contrary, that scientific work is indispensable to
  Russia, and I wish from my heart that future conditions may become
  more favourable than in the time of which I have spoken in the above
  lines.

Soon he was able to appreciate the great French qualities: humanitarian
manners, tolerance, and gentleness, real freedom of thought, loyal and
courteous intercourse, all of which made life easy and agreeable. And
most precious of all were the true friendships which he contracted with
his colleagues and his pupils. Indeed the Institut Pasteur and France
became for him a second Motherland, and when in later years he was
invited to other countries with more liberal conditions, he habitually
replied that only for one place would he leave the Pasteur Institute,
"the neighbouring cemetery of Montparnasse."

However, after his death, the Pasteur Institute which he had so loved
continued to give him hospitality and harboured his ashes....

Pasteur himself ever was most kind and helpful to Metchnikoff. During
the first years, when his health still allowed it, he used often to
come to the laboratory, questioning Metchnikoff on his researches with
much interest and always warmly encouraging him. He even attended
assiduously his course of lectures on inflammation. After his state
of health no longer allowed him to go out, Metchnikoff used to visit
him every day, and tried to cheer him by talking to him of current
researches.

MM. Duclaux and Roux became his closest friends; they were at first
brought together by scientific interests and by questions concerning
the Institute; but, gradually, personal sympathy grew up between them,
binding them by that solid bond which is made up of daily occurrences,
inducing respect, confidence, and affection. Moreover, Metchnikoff felt
the deepest gratitude towards Pasteur and his collaborators, who had
given him the possibility of working in so favourable an atmosphere.

From the very first, Pasteur sympathised with the phagocyte theory;
the other members of the Institute thought it too biological, almost
vitalistic. But when they had made themselves thoroughly cognisant with
it, they also adopted it. Thus, having found in the Pasteur Institute
not only favourable working conditions but also moral support,
Metchnikoff became deeply attached to it, and the interests of "the
House" became his.

In 1915, on the occasion of Metchnikoff's seventieth anniversary, M.
Roux, in a Jubilee speech, gave of him and of his work the following
appreciation which describes, better than anything I could say, what
his part was in the Pasteur Institute:

  In Paris as in Petrograd, as in Odessa, you have become a leader of
  thought, and you have kindled in this Institute a scientific focus
  which has radiated afar.

  Your laboratory is more alive than any in the house; workers come
  to it in crowds. There, the bacteriological events of the day are
  discussed, interesting preparations examined, ideas sought for that
  may help an experimenter to solve difficulties in which he has become
  involved. It is to you that one comes to ask for a control experiment
  on a newly observed fact, for a criticism of a discovery that does
  not always survive the test.

  Moreover, as you read everything, every one comes to you for
  information, for an account of a newly published memoir which there
  is no time to read. It is much more convenient than to consult
  the library and also much safer, for errors of translation and
  interpretation are avoided.

  Your erudition is so vast and so accurate that it is made use of by
  the whole house. How many times have I not availed myself of it?
  One never fears to take advantage of it, for no scientific question
  ever finds you indifferent. Your ardour warms the indolent and gives
  confidence to the sceptical.

  You are an incomparable collaborator as I know, I who have had the
  good fortune of being associated with your researches on several
  occasions. Indeed, you did nearly all the work!

  More even than your science, your kindliness attracts; who amongst us
  has not experienced it? I have had a touching proof of it when, many
  times, you have nursed me as if I were your own child. You are so
  happy in doing good that you even feel gratitude towards those whom
  you serve.

  This is such an intimate gathering that I may be allowed to say quite
  openly that it is so painful to you not to give that you prefer being
  exploited rather than close your hand.

  The Pasteur Institute owes you much; you have brought to it the
  prestige of your renown, and by your work and that of your pupils
  you have greatly contributed to its glory. You have given a noble
  example of disinterestedness by refusing any salary in those years
  when the budget was balanced with difficulty and by preferring to the
  glorious and lucrative situations that were offered to you the modest
  life of this house. Still a Russian by nationality, you have become
  French by your choice, and you contracted a Franco-Russian alliance
  with the Pasteur Institute long before the diplomats thought of it.

At the beginning the members of the Pasteur Institute were few, and
the association bore a quasi-family character, Pasteurians often being
compared with a monastic order, united by the worship of science. The
progressive growth of the Institute inevitably destroyed its character
of intimacy, but it remained a precious scientific focus, and this is
what Metchnikoff said of it in 1913, _à propos_ of the twenty-fifth
anniversary of its foundation:

  If we weigh the for and against of the Pasteur Institute, it is
  indisputable that the first surpasses the second by a great deal. I
  do not think another institution exists that is equally favourable
  to work. Innumerable proofs have been adduced to attest this in the
  twenty-five years that our House has existed.

It was especially the development of pure scientific research in the
Institute which interested Metchnikoff; he continually considered means
of contributing towards it; he thought it necessary to attract active
scientific forces regardless of their origin, to institute generous
scientific "scholarships," and to stimulate by every means scientific
activity and spirit.

As the rapid development of bacteriology necessitated having recourse
to chemistry, physics, and physiology, he considered it indispensable
to organise collective work in which specialists in these divers
branches should take part, thus collaborating to the solution of
the same problem. Later he was able to realise this project, up to a
certain point, in his own laboratory, when studying intestinal flora.

He thought it would be useful to extend this method, as far as
possible, to researches such as that on tuberculosis and on cancer,
such researches being complicated and protracted and demanding
co-ordinate efforts and an organisation that should prevent the
repetition of individual first steps. A clinic attached to the
Pasteur Institute and adapted to scientific researches seemed to him
indispensable.

He also considered that the experimental study of those human diseases
which can only be inoculated in anthropoid apes should be carried out
through the breeding of those animals in the colonies, for infantile
diseases demand very young apes as subjects for experiments, and they
cannot be brought to Europe in sufficient numbers without great loss. A
mission of workers might carry out experiments on the spot.

He thought the popularisation of science a very useful thing and wished
the Pasteur Institute to participate in it by appropriate courses of
public lectures. He attached great importance to the penetration into
ordinary life of results acquired by science, for the struggle against
disease consists chiefly in prophylactic and hygienic measures which
can only be applied by a well-informed public. For that reason he was
always willing to be interviewed on scientific questions by journalists
and, indeed, by any one, however ignorant. In order to instruct the
public he often wrote popular articles on questions of hygiene and
medicine.

Science in general never was a dead letter for him; his most abstract
conceptions were always narrowly bound to life; he saw one through the
other and considered that they should serve each other.

Apart from scientific researches, he took part in the courses given at
the Pasteur Institute. He prepared his lectures with infinite care,
and, in spite of his long experience, he never could give them without
some nervousness, especially during the last years of his life. He used
even to write down the first sentences and to read them out in order
to give himself time to recover; but very soon his self-control would
return, and he would proceed with animation and lucidity; his lectures
were living and suggestive.

I have mentioned above Roux's masterly appreciation of his influence at
the Pasteur Institute. The following was written to me, a year after
Metchnikoff's death, by one of his closest disciples and collaborators,
and describes in a vivid manner the deep feelings with which he
inspired his pupils:

  "You say that you love to think that he continues to live in
  others. Could it have been otherwise? A character as powerful as
  his is capable of influencing and illuminating the life, not of one
  individual, but of a whole generation. I look upon it as the greatest
  good fortune of my life that I was able to spend my best years in his
  orbit and to impregnate my mind with his spirit, not his scientific
  spirit, but that which he manifested in facing life and humanity.

  "This bond has become so much part of myself that my first impulse
  is always to act in the way he would have approved. I even feel the
  need to share with others what I received from him. I do not know
  whether it will be given to me to solve certain problems posed by
  him, but I have the conviction that his spirit, in its purity, will
  be preserved among us. He will ever live in those who worked by his
  side, and in those who will come to work in his laboratory. It cannot
  be otherwise."

Metchnikoff on his part never remained indifferent to his pupils. His
solicitude towards them was warm, sometimes paternal, always ready and
active. Many of his pupils remained his friends and collaborators for
years afterwards. His fiery and exclusive temperament, however, made
him take up a very different attitude in exceptional cases, when he
found himself in front of one who persisted in a path which Metchnikoff
himself considered the wrong path, or before an action which he thought
disloyal or work done without conscience. Then he became beside
himself, and positively dangerous to those who had exposed themselves
to the paroxysm of his indignation.

Fortunately such cases were rare; as a general rule, the atmosphere of
his laboratory was impregnated with scientific spirit and ardour; all
forces in it converged towards the same goal, being bound together by a
community of aspirations and activity of which he was the soul.

       *       *       *       *       *

The first period of his life in France was taken up by the
strengthening and development of the phagocyte theory and by an eager
struggle in its defence. He displayed in it his full energy as a
scientist and a fighter, and this was perhaps the most agitated, the
most tense period of his life.

When at last his theory was securely established and began to be
accepted, he continued his researches with the same passionate ardour
but in an atmosphere of peace. It was joy and bliss to him to be able
to work apart from other preoccupations, and the years of his life
between fifty and sixty were the happiest he ever had.

The state of his soul and his ideas had considerably evolved in the
course of years; the great moral and physical sensitiveness which had
so often made him miserable in his youth had decreased and he had
become much less impulsive. Unpleasant sensations no longer caused him
so much suffering; he could bear the mewing of a cat or the barking of
a dog; personal vexations no longer made him take such a horror of life
as to wish to be rid of it: he now merely tried to conquer them.

At first this change operated less upon his ideas than upon his
sensations and sentiments. Accustomed as he was to analyse his
emotions, he realised the development within himself of a new sense of
appreciation; less sensitive now to extreme impressions, he had become
more so to ordinary ones. For instance, though less enchanted by music,
and less irritated by discordant noises, he enjoyed absolute calm more
fully. Now indifferent to rich food, which he formerly used to enjoy,
he appreciated simple fare, bread and pure water. He did not seek for
picturesque sites but took infinite pleasure in watching the growth of
grass or the bursting of a bud. The first halting steps or the smile of
an infant charmed and delighted him.

Demanding less from life, he now appreciated it as it was, and
experienced the joy of mere living. The instinct, the sense of life
had been born in him. He now saw Life and Nature under a different
aspect from that which they had borne for him in his youth, for he had
gradually acquired more balance; he had become adapted.

In their turn, his ideas evolved towards a more optimistic conception
of life. His reflections, freed from the yoke of his juvenile
sensitiveness, tended towards the possibility of a correction of the
disharmonies of human nature through knowledge and will. This evolution
had taken years. "In order to understand the meaning of life," he said,
"it is necessary to live a long time, without which one finds oneself
in the position of a congenitally blind man before whom the beauties of
colour are spread out."

       *       *       *       *       *

During the twenty-eight years that he lived in France, nearly all his
time was devoted to the laboratory. Whilst the Institute was still in
its beginning, work there was calm and collected; but, as its growing
renown attracted many people, this quietude decreased considerably.
Metchnikoff felt this, but could not bring himself to refuse to admit
those who came; he compensated himself by peaceful Sundays and holidays.

For a long time we inhabited the neighbourhood of the Institute and
spent the summers at Sèvres; in 1898 we bought a small villa there with
a sum of money which we inherited from an aunt. In 1905 we settled
there altogether, for Metchnikoff, confined in the laboratory all day,
felt the need of fresh air; the daily walk that he was obliged to take
to reach the house and the absolute calm, away from the noise of the
city, suited him; he even fancied that the hill on which the house was
built provided him with a wholesome exercise for his heart.

The return to Sèvres, which he greatly liked, was to him a daily source
of pleasure. I can see him now, hastily coming out of the train, his
pockets full of papers and brochures which he read in the train and
parcels in his hands, for he loved to bring home little presents. A
kindly smile illumined his face and he never failed to express the
pleasure he felt at coming home. "How pure the air is! How green the
grass! What peace! You see, if I did not go to Paris to work I should
not be so alive to the charm of Sèvres and the pleasure of rest." He
used to come home at seven and do no more work; it was his daily rest.
He then gave himself up to complete relaxation, joked, related the
incidents of the day, spoke of his researches, planned experiments
for the next day, read aloud part of the evening and then listened to
music, not only because he liked it, but also because he wanted to
"switch on to another line," _i.e._ rest his mind completely.

He was an incomparable companion, always alive and communicative,
generously giving out the treasures of his heart and his intelligence.
He liked a simple life; all artifice, all convention displeased him. He
disliked luxury in his person to that extent that he never consented
to possess a gold watch nor any object with no particular use. His
only luxury was to gratify others. He enjoyed peaceful family life and
a circle of intimate friends. Yet, appreciating as he did all serious
manifestations of life, he was glad to have the opportunity of meeting
people who were interesting either in themselves or for the knowledge
which they could impart.

In Life as in Science he found precepts to help the evolution of his
moral and philosophical ideas, which he placed in their turn at Life's
service. If he could not solve a problem, he at least pointed out its
importance.

His attentive penetration of things in themselves, coupled with a
creative imagination, was the force which enabled him to open out new
prospects and new paths.

On looking back upon his own life, he used to say that the period spent
at the Pasteur Institute had been the happiest, the most favourable to
his scientific work; he therefore remained deeply attached to it until
the end of his life.




                             CHAPTER XXIII

  Opposition to the phagocyte theory--Scientific controversies
  --Experiments in support of the phagocyte theory--Behring and
  antitoxins--The London Congress--Inflammation.


As long as Metchnikoff was but a zoologist, the scientific atmosphere
around him remained calm and serene. But everything changed suddenly
when he entered the domain of pathology with his theory of phagocytes
and phagocytosis.

Here was the realm of secular traditions, deeply rooted, and of
theories generally admitted but resting on no biological basis. Attacks
and objections against his theories came following upon each other
with a rush, only to be compared with the racing clouds of a stormy
sky or the hurrying waves of a tempestuous sea. An epic struggle began
for Metchnikoff which was to last for twenty-five years, until the
moment when the phagocyte theory, his child now grown up, emerged
victoriously. To each attack, to each objection, he answered by fresh
experiments, fresh observations annihilating objections; his theory
was assuming a wider and wider scope, becoming more solid, more
convincing.... But only his intimates knew how much the struggle cost
him in vital force, what sleepless nights, due to continuous cerebral
tension and to the effort to conceive some new and irrefragable
experiment, what alternations of hope and depression.... In an ardent,
stormy life such as this, each year counted for many.

As soon as he arrived at the Pasteur Institute he undertook active
researches with the object of developing and defending the phagocyte
theory.

By experiments on the _rouget_ of pigs he refuted the objections of
Emmerich, who affirmed that, in that disease, the destruction of the
microbes was not due to phagocytes. By experiments on the anthrax
of pigeons he answered the attacks of Baumgarten and his pupils. To
Behring, who affirmed that immunity was due to the bactericidal power
of the serum, he replied by a series of experiments on the anthrax of
rats.

By all these researches Metchnikoff proved that recovery and immunity
depended on the absorption and digestion of _living, virulent_ microbes
by phagocytes. Natural or artificial vaccination by attenuated microbes
allows the phagocytes to become gradually accustomed to digest more
virulent ones, and this confers immunity upon the organism. That
phenomenon is comparable to that by which we can accustom ourselves
gradually to doses of poison which would be very harmful if taken at
the start (arsenic, opium, nicotine, etc.).

Little by little, the accuracy of Metchnikoff's observations began to
be realised, and, moreover, other scientists supported him by their
personal investigations. The part played by phagocytosis was becoming
more and more evident and the question was ripening in France and in
England, but in Germany it still met with great opposition.

At the Berlin Congress in 1890 the theory was received very favourably
by Lister, whilst Koch attacked it, trying to prove that phagocytes
played no part in immunity, which, according to him, depended upon the
chemical properties of the blood.

Soon after that, Behring discovered antitoxins, and this seemed to
favour the chemical or humoral theory of immunity. According to the
latter, microbes and their poisons were rendered harmless by the
chemical properties of the blood serum, properties similar to those of
disinfecting substances.

In spite of his firm conviction of the solidity of the phagocyte
theory, this discovery was a shock to Metchnikoff, for it was in
apparent contradiction with the cellular theory of immunity. He
hastened to undertake a series of researches; his overflowing eagerness
infected his whole circle, every one taking the warmest interest in the
progress of his experiments.

This was just as preparations were being made to take part in the
London Congress, where the question of immunity was to be debated and
had indeed been placed at the head of the programme. Many papers were
being prepared, and a veritable tourney of opinions was to take place
at this Congress.

Metchnikoff had already been to England once, in the spring of
1891, on the occasion of his reception as an Honorary Doctor by the
University of Cambridge. This gave him the opportunity of making closer
acquaintance with the English, who inspired him with great sympathy;
years only increased this feeling. He appreciated the originality of
their earnest and generalising spirit, their loyalty and energy; he was
grateful to them for the attentive and favourable attitude with which
his scientific work and himself had been received.

He was therefore delighted that this Congress, which was to be the
scene of his final struggle against his contradictors, should take
place in England and not in Germany, a country hostile to his ideas.

In view of the importance of the coming debate, a series of fresh
experiments was made. This time Metchnikoff undertook them not only in
person, but also in collaboration with M. Roux and with some students.
The whole laboratory was in a state of effervescence.

The principal papers to be read at the Congress on the question of
immunity were those of Messrs. Roux and Büchner, the first entirely in
favour of the phagocyte theory and the second supporting the humoral
theory.

Metchnikoff read an epitome of his researches and of his answers to
attacks on his theory. Towards the end of the Congress the latter had
visibly acquired the suffrage of numerous scientists. Roux wrote to me
from London concerning my husband's paper:

  Metchnikoff is busy showing his preparations and, besides, he would
  not tell you how great is his triumph. He spoke with such passion
  that he carried everybody with him. I believe that, this evening, the
  phagocyte theory is the richer by many friends.

Thus the researches made in recent years and the results of the London
Congress allowed us to consider the phagocyte theory of immunity as
being solidly established.

Yet, Behring's discovery of antitoxins still hung over it like a
sword of Damocles; it was imperative that the respective parts played
by antitoxins and by phagocytes should be elucidated. With that
object in view, Metchnikoff undertook new researches and succeeded in
ascertaining once for all the narrow link between immunity and the
function of the phagocytes which probably elaborate the antitoxins as a
product of their digestion of vaccinal toxins. He drew this conclusion
from the fact that, in a rabbit vaccinated against hog-cholera, the
exudate devoid of phagocytes[20] is neither bactericidal, nor antitoxic,
nor attenuating, while it is so if it contains phagocytes. Therefore a
relation of causality exists between cells and the acquired properties
of humors. And the resistance of the animal is in visible correlation
with the degree of phagocytosis which is manifested by it.

  [20] Aqueous humor, the exudate of aseptic oedemata.

These results having been established, it seemed as if the last rampart
of the humoral theory had been taken by storm.

In the meanwhile the persistent and bitter opposition of physicians to
the phagocyte theory made a great impression on Metchnikoff, and, while
stimulating his energy in defence of his ideas, it maintained him in a
state of nervous excitement and even depressed him.

He asked himself why this obstinate opposition to a doctrine based on
well-established facts, easily tested and observed throughout the whole
animal kingdom? To him, a naturalist, it seemed clear and simple and
all the more admissible that it was confirmed by the generality of its
application to all living beings.

But, he thought, perhaps the real cause of the attitude of the
contradictors lies in the very fact that medical science only
concerns itself with the pathological phenomena of higher animals,
leaving their evolution entirely out of account, as well as their
starting-point in lower animals--whilst it is the very simplicity of
the latter which allows us to penetrate to the origin of the phenomena.

Perhaps a general plan of the whole, in the shape of a comparative
study, embracing the whole animal scale, would throw light over the
generality of phagocytic phenomena and would make their continuity
understood through normal and pathological biology. He determined to
make this effort. In order to place in a fresh light the biological
evolution of phagocytosis phenomena _in disease_, he chose one of the
principal manifestations of pathological phagocytosis, _inflammation_,
and, in 1891, gave a series of lectures on this subject which he
afterwards published in a volume. According to his usual method, he
began by the most primitive beings, taking as a starting-point the
lower organisms which do not yet possess differentiated functions, and
whose normal digestion is, if necessary, used as a means of defence
against noxious agents. Then, by a comparative study in every grade
of the animal kingdom, he proved that the same mode of struggle and
defence persists in the mesodermic cells, the phagocytes in all
animals in general. In all of them, thanks to a special sensitiveness,
_Chimiotaxis_, phagocytes move towards the intruder, to englobe it and
digest it if they can. This reaction for defence by the organism takes
place in beings endowed with a vascular system by the migration of the
blood-phagocytes which traverse the walls of the blood-vessels in order
to betake themselves to the invaded point.

In higher animals, all the symptoms which accompany this phenomenon of
defence and which constitute the classical picture of inflammation
(a heightened temperature, pain, redness, tumefaction) are due to the
complexity of the organism; but the _essence_, the _primum movens_
of inflammation, with them also, is a _digestive_ action of the
phagocytes upon the noxious agent, therefore a salutary reaction of
the organism, essentially similar to the normal digestion of inferior
beings. Metchnikoff adduced numerous examples giving evidence of the
genetic link which exists between inflammation and normal intracellular
digestion, and while establishing the evolution of the former on
biological and experimental bases, he showed at the same time the close
connection which binds normal biology and pathological biology.

This series of lectures formed a volume which appeared in 1892 under
the title of _Leçons sur la pathologie comparée de l'inflammation_, a
book which contributed to the acceptation of the phagocyte theory and
which showed the importance of Natural History applied to Medicine.




                             CHAPTER XXIV

  Cholera--Experiments on himself and others--Illness of M. Jupille
  --Death of an epileptic subject--Insufficient results.


The acute period of the struggle in defence of the phagocyte theory
now seemed to have come to an end and Metchnikoff turned his thoughts
towards a new field of ideas.

Having elucidated the essence of inflammation, he wished to study the
origin of another pathological symptom, _i.e._ the rise in temperature
which constitutes a feverish condition. To that end he undertook a
succession of experiments on cold-blooded animals; he injected microbes
into crocodiles and serpents, hoping thus to provoke a rise in their
temperature. But those experiments did not give the results expected.

In the meanwhile (1892) cholera had made its appearance in France; the
specificity of the cholera vibrio was not finally established at that
time. The observations made by Pettenkoffer on the immunity of certain
regions, despite the presence of the cholera vibrio in the water, and
the experiments made upon himself by that scientist, seemed to plead
against the specificity of the cholera vibrio; but other facts spoke in
its favour. Desirous of solving this question, Metchnikoff went to a
cholera centre in Brittany in order to fetch the necessary materials.
Having done so, he attempted to produce cholera in divers kinds of
animals, but without success.

As he failed to solve the problem of the specificity of the cholera
vibrio on animals, he resolved to experiment upon himself and consumed
a culture of cholera vibriones. He did not contract cholera, which made
him doubt the specificity of the vibrio, and therefore he consented to
repeat the experiment on one of his workers (M. Latapie) who offered
to submit to it: the result was the same. He then did not hesitate to
accept the offer of a second volunteer (M. Jupille). The preceding
results having led him to suppose that the cholera vibrio became
attenuated _in vitro_ and might perhaps serve as a vaccine against
cholera, he gave a culture of long standing to the young volunteer.

To his astonishment and despair, Jupille began to manifest the typical
symptoms of cholera, and a doctor who was particularly conversant
with the clinical chart of the disease declared the case a severe one
because of the nervous symptoms which accompanied it.

Metchnikoff was in mortal anxiety, and even said to himself that he
could not survive a fatal issue. Fortunately the patient recovered,
and this terrifying experiment proved indisputably the specificity of
the cholera vibrio. Yet the irregularity of its action showed that in
certain cases conditions existed which prevented the inception of the
disease, and Metchnikoff supposed that this might be due to the action
of the different intestinal micro-organisms.

In order to simplify the question, he began by making experiments
outside the organism. He sowed the cholera vibrio with divers other
microbes and saw that some of them facilitated its culture whilst
others prevented it. Similar experiments within the organism of animals
gave no conclusive results; the simultaneous ingestion of the cholera
vibrio and of favourable microbes did not induce cholera.

The flora of the intestines, complex as it is, probably played a part
on which it was difficult to throw any light. Yet Metchnikoff did not
give up the idea of producing a vaccine against this disease with
attenuated microbes, or, if not, to prevent its inception by preventive
microbes. His thesis was strengthened when one of his pupils, Dr.
Sanarelli, discovered a series of choleriform bacilli in the absence of
any cholera epidemic, one of those microbes being found at Versailles,
a town which had remained immune during every cholera epidemic.

Metchnikoff thought that this microbe, or some choleriform bacillus,
similar though not specific, probably served as a natural vaccine
against cholera in those localities which were spared by the epidemic
though the cholera vibrio was brought there. This was a question that
could only be solved by experiment.

At the time when he had himself absorbed a cholera culture, Metchnikoff
admitted the risk of catching the disease; still, his eagerness to
solve the problem had silenced in him all other considerations and
feelings opposed to his irresistible desire to attempt the experiment.
This "psychosis," as he himself called it later, recurred now, in spite
of all the emotions he had gone through on the previous occasion, and
he decided once again to experiment on man. It is true that he now
only had to deal with choleriform microbes from Versailles which he
believed to be quite harmless as they came from the water of a locality
free from cholera. He therefore ingested some of the Versailles
choleriform vibriones and gave some to several other people. Contrary
to expectation, one of the latter, an incurable epileptic, showed some
symptoms of cholera, but recovered. But as, a short time later, this
patient died from a cause which remained obscure, Metchnikoff thought
that possibly the experiment might have had something to do with it,
and finally resolved to perform no other experiments on human beings.

How could that unforeseen result be explained? Metchnikoff supposed
that the intestine of the subject contained favourable microbes
which had exalted the virulence of the bacillus, in itself weak
and innocuous. If it were so, then certain intestinal microbes
would influence the inception of diseases and the action of the
micro-organisms would vary according to the society in which they found
themselves. As such problems could only be solved through experiment,
he again energetically sought for a means of conferring cholera upon
animals. After many failures and difficulties, it occurred to him to
try new-born animals whose intestinal flora, not yet developed, could
not interfere with the swarming of the ingested bacilli. He chose young
suckling rabbits for his experiments and, with the aid of _favourable_
microbes, he succeeded at last in giving them characteristic cholera,
through ingestion; thus it became possible to study intestinal cholera
on these animals.

However, numerous researches on the prevention of cholera by means
of divers microbes gave no results sufficiently conclusive to permit
their application to human beings. The problem was rendered extremely
complicated and difficult by the many and varied influences of numerous
intestinal microbes and the inconstancy of microbian species in the
same individual.




                              CHAPTER XXV

  Pfeiffer's experiments, 1895--The Buda-Pest Congress--Extracellular
  destruction of microbes--Reaction of the organism against toxins--
  Dr. Besredka's researches--Macrophages--The Moscow Congress, 1897--
  Bordet's experiments.


Metchnikoff had scarcely recovered from all the emotions caused by his
experiments on cholera, which he was still studying, when, in 1894, a
work appeared by a well-known German scientist, Pfeiffer, bringing out
new facts in favour of the extracellular destruction of microbes.

Whilst studying the influence of the blood serum within the organism
and not outside it as his predecessors had done, he had found that
cholera vibriones, injected into the peritoneum of a guinea-pig
vaccinated against cholera, were nearly all killed in a few minutes
and that they then presented the form of motionless granules in
the peritoneal liquid. This granular degenescence, said Pfeiffer,
took place apart from the phagocytes and therefore without their
intervention. Metchnikoff repeated the experiment at once and
ascertained that it was perfectly accurate.

The complexity of biological phenomena being very great, he fully
admitted the possibility of other means of defence in the organism
besides that of the phagocytic reaction. However, this new fact
disagreed so much with his own observation, and seemed so isolated,
that Metchnikoff supposed an error of interpretation must have been
made and tried to throw light upon it. He spent sleepless nights
seeking the conclusive experiment which might explain Pfeiffer's
phenomenon.

His excitement was all the greater that he was very soon going to the
International Congress at Buda-Pest, where he intended to expose the
results of his new researches, and he feared that he should not have
time to make all the experiments which he required in support of his
arguments. However, the general impression of the Congress was clearly
favourable to the phagocyte theory. This is how M. Roux picturesquely
described the scene at Metchnikoff's Jubilee in 1915:

  "I can see you now at the Buda-Pest Congress in 1894, disputing
  with your antagonists; with your fiery face, sparkling eyes, and
  dishevelled hair, you looked like the Dæmon of Science, but your
  words, your irresistible arguments raised the applause of your
  audience.

  "The new facts, which had at first sight seemed to contradict the
  phagocyte theory, now entered into harmony with it. It was found to
  be sufficiently comprehensive to reconcile the holders of the humoral
  theory with the partisans of the cellular theory."

This is how Metchnikoff had reconciled the apparent disagreement of
Pfeiffer's phenomenon with the phagocyte doctrine: he demonstrated,
by a series of experiments, that the extracellular destruction of
the cholera vibriones in the peritoneum of a guinea-pig vaccinated
against cholera, did in no wise depend on the _chemical_ properties
of the blood serum, but was simply due to the digestive juices which
had escaped from the inside of the leucocytes, damaged by the
intraperitoneal injection. Those digestive juices, or _cytases_, poured
into the peritoneal liquid were what killed the injected cholera
vibriones and transformed them into "Pfeiffer's granulations." On the
other hand, if by means of various precautions the phagocytes were left
unmolested, the extracellular destruction did not take place and the
vibriones were digested within the phagocytes.

Metchnikoff used other experiments to prove that the bactericidal
property of blood juices did not exist without intervention from the
phagocytes. For instance, in a guinea-pig vaccinated against cholera,
the bacilli are not destroyed if they are injected into parts of the
organism that are devoid of pre-existing phagocytes, such as in the
subcutaneous tissue, in the anterior chamber of the eye or in an
aseptically-obtained oedema. On the other hand, if, in the same
medium, some exudate is injected containing damaged leucocytes from
which the digestive juice is leaking, the vibriones introduced are
destroyed. The same results are obtained _in vitro_.

All these experiments proved that the extracellular destruction of
the cholera vibrio was accomplished by the digestive juices which had
passed from the phagocytes into the humors and not at all through a
special property of those humors. Once again the phagocyte theory rose
triumphant from the test.

After having finally proved that it is by means of its phagocytes that
the organism fights _microbes_, Metchnikoff wished to find out whether
it was by the same process that it struggled with their poisons, or
_toxins_. This problem, far more difficult to solve, took him many
years' study. Whilst every phase of the phagocytes' struggle against
microbes can be followed with the eyes, it is impossible to do so
where poisons are concerned, since they are invisible; it is necessary
to proceed by a different road.

Faithful to his method of taking as a starting-point the simplest
expression of the phenomenon to be studied, Metchnikoff began by
lower beings. Unicellular organisms, such as myxomycetes, amoebæ,
and infusoria, sometimes manifest a natural immunity to certain
poisons. It is also possible to endow them with artificial immunity
by accustoming them gradually to substances which, ingested straight
away, would infallibly have killed them. Such phenomena, seen in
unicellular beings, could only be ascribed to the reaction of the cell
itself. Therefore Metchnikoff supposed _a priori_ that the phagocytes,
being similar primitive cells of multicellular beings, would also
react against poisons. And, in fact, he ascertained that the number
of phagocytes in a rabbit's blood diminished considerably under the
influence of a fatal dose of arsenic, whilst it increased under the
influence of small doses of the poison, to which it was possible to
accustom the animal.

Dr. Besredka, a disciple of Metchnikoff, made some very interesting
researches, which entirely confirmed the share of the phagocytes in the
reaction against sulphides of arsenic. He had chosen the trisulphide,
a very slightly soluble salt of an orange colour, in order to find it
again easily within the organism. After having injected non-fatal doses
of it into the peritoneal cavity, he obtained an exudate in which all
the orange granules of the salt were to be found included within those
leucocytes which have a large, non-lobed nucleus--the _macrophages_.
These cells gradually digested the salt they had englobed, which ended
by disappearing entirely within them, and the rabbit remained safe and
sound. On the other hand, it died if the same doses of the same salt
had been protected from the leucocytes by an elderberry bag, or when
the leucocytes had been attracted elsewhere by a previous injection of
carmine for instance. Those experiments removed all doubts as to the
share of the phagocytes in the destruction of mineral poisons.

Certain experiments on _microbian_ poisons spoke in the same sense.
Thus MM. Roux and Borrel had observed that the diphtheritic toxin,
which is inoffensive to rats even in large doses, kills that animal
if a small quantity of it is introduced into the brain, the probable
explanation being that, in cases of subcutaneous injections, the
poison, "phagocyted" on the way, was destroyed before it reached the
nerve cells.

Thus experiments seemed to plead in favour of the view that the part
played by phagocytosis is not limited to the struggle against microbes,
but also extends to the defence against poisons and toxins.

       *       *       *       *       *

After having studied the mode of destruction of these, Metchnikoff
wished to elucidate the origin of the counter-poisons, the specific
antitoxins discovered by Behring in the humors of immunised organisms,
a question of which the study was even more difficult.

Metchnikoff began by asking himself whether the microbes themselves
did not produce antitoxins in order to defend themselves against enemy
micro-organisms. He made many experiments but only obtained negative
results, and concluded that the antitoxins must be manufactured by the
organism itself.

The origin of this property must be more recent than that of the
phagocytic reaction, for it does not exist in plants or in inferior
animals. It was only from superior cold-blooded vertebrates, such as
the crocodile--and that only in artificial conditions--and upwards,
that Metchnikoff succeeded in finding a specific antitoxic power in the
humors.

He ascertained that the vaccination of animals by toxins conferred,
after a time, antitoxic powers to the blood and humors _which contained
leucocytes_. He concluded therefrom that the presence of antitoxins
depended on that of the phagocytes. Experiments on divers higher
animals having proved that, in them also, antitoxins were localised
in _humors containing phagocytes_, Metchnikoff concluded that the
antitoxins were manufactured by the cells themselves. As toxins are
absorbed and digested chiefly by _macrophages_, it is probable that
it is the latter also which manufacture specific antitoxins, or the
final product of the digestion of corresponding toxins. Metchnikoff
could only propound this idea as an hypothesis, for the complexity and
difficulty of a material demonstration did not yet allow of a definite
solution of the problem. However, certain observations on toxins and
antitoxins pleaded in favour of this thesis.

For instance, working in collaboration with MM. Roux and Salimbeni, he
had found that it is by soluble poisons that the cholera vibrions harm
the organism or kill it, but that small doses of the same _poisons_
are vaccines and make the blood of the vaccinated animal _antitoxic_.
On the other hand, a _microbian_ vaccination is preventive against
_microbes_ only but not against toxins and the blood does not become
antitoxic. This is explained by the fact that it is not the same cells
which digest cholera microbes and cholera toxins: the _microphages_
digest the vibriones whilst the _macrophages_ digest the poisons and,
probably, manufacture as products of this digestion, the corresponding
antibody, the cholera antitoxins.

On the contrary, in cases of the inclusion of _microbes_ by
_macrophages_, as, for instance, in plague, the blood acquires an
_antitoxic_ power by injection of the microbes themselves and not by
their toxins, as was demonstrated by M. Roux and his collaborators. The
same fact was observed by Metchnikoff on the alligator, in whom also
microbes are digested by _macrophages_. In those cases, when microbes
and toxins are digested by the same cells, the latter manufacture
antibodies against both.

These facts rendered legitimate the supposition of the macrophagic
origin of antitoxins.

       *       *       *       *       *

In 1897 an International Congress took place in Moscow. Metchnikoff
read a paper on the phagocytic reaction against toxins and another
dealing with the whole of the knowledge acquired concerning human
plague. He ended this by a plea in favour of Science, so often accused
of having contributed nothing to the solution of the most important
human problems, particularly ethical ones, and of having, on the
contrary, sanctioned the law of Might by tabulating the laws of the
struggle for existence. Metchnikoff objected that, far from doing
so, Science, by revealing the laws of Nature, applied to humanity
the benefits derived from them, whilst striving to counterbalance
their cruel or harmful effects. The struggle against plague and other
diseases was a concrete example of this, for here medical science
opposed itself to the cruelty of "natural selection." He wound up
his speech by the following words, "Just as, in order to satisfy his
æsthetic tastes, Man revolts against the laws of Nature which creates
races of sterile and fragile flowers, he does not hesitate to defend
the weak against the laws of natural selection. Science has been
faithful to her mission and to her generous traditions. Let her, then,
progress unhindered."

Metchnikoff's friend and companion, M. Nocard, wrote to me concerning
Metchnikoff's paper:

  Do not believe a word that Metchnikoff tells you. He had tremendous
  success. The somewhat free form of his paper contributed to its
  success, as it only made his conviction and enthusiasm more apparent.
  Thus the Sibyl on her tripod.

Metchnikoff had at this period a very talented disciple, M. I. Bordet,
who opened a new path by a series of researches of the greatest
importance. He found, among other things, that "the figured elements"
can be destroyed outside the cells, in the humors. Thus, if red blood
corpuscles from one animal are injected into an animal of a different
kind, these globules are destroyed, not within the phagocytes,
but outside them, in the ambient humors. Metchnikoff studied this
phenomenon and proved that the explanation was the same that he had
previously given of Pfeiffer's phenomenon in the case of cholera
vibrions. In Bordet's experiments, the leucocytes which were already
existing in the humors were also damaged by the experimental shock;
but, if this was carefully avoided, the phagocytes, remaining intact,
englobed and digested the injected red corpuscles and no phenomenon
similar to Pfeiffer's took place.

These observations led Metchnikoff to a thorough study of the
destruction of cellular elements by the phagocytes. He had already
observed that, whilst the struggle with microbes is chiefly undertaken
by small leucocytes with a lobed nucleus--the _microphages_--it is
the great leucocytes with a single large nucleus--the so-called
_macrophages_--which undertake the destruction of cells, "figured"
elements, as well as that of toxins. The _macrophages_ are to be
found not only in the blood but also in different organs such as the
liver, spleen, kidneys, etc.; they seize upon living cells by means
of mobile protoplasmic prolongations with which they draw them in and
end by ingesting them completely. Not only do they thus absorb foreign
cellular elements such as red corpuscles, spermatozoa, etc., but also
all the weakened cells of the organism itself.

This weakening may be due to normal phenomena such as the metamorphosis
of insects or tadpoles, when certain organs, as they weaken,
become useless or inactive. But, oftener, this weakening is due to
pathological causes, as in morbid atrophies or poisoning by microbian
toxins. In any case, the enfeeblement of cells exposes them to be
devoured by macrophages, which brings about the atrophy of the cells or
even of the organs which contain them.

These observations suggested to Metchnikoff the idea that senile
atrophy might be due to the same mechanism, and his thoughts turned
towards the problem of the causes of old age.

But, before undertaking researches in a new direction, he wished to
conclude those he had been pursuing for twenty years on the phenomenon
of phagocytosis. He therefore started to complete his investigations on
immunity in order to epitomise them and to give a definite form to his
doctrine on that subject.




                             CHAPTER XXVI

  1900. Immunity--Natural Immunity--Artificial Immunity.


For centuries the question of immunity has occupied the human mind
because the prevention of disease has ever been one of the greatest
preoccupations of Man. Savages had already observed that man can become
refractory to the venom of serpents, either through a slight bite or
by the application of certain preparations of that venom on scarified
skin. It was also a popular and very ancient notion that the contact
of a slightly scratched hand with the pustules of cow-pox conferred
immunity against human small-pox. It was on this observation that
Jenner founded his method of antivariolic vaccination. The latter, in
its turn, suggested to Pasteur the idea of attempting antimicrobian
vaccinations. Having ascertained that old cultures of chicken cholera,
previously very virulent, had become harmless, he wondered whether
they had become a vaccine and proved by experiment that they had. That
led him to the principle of the attenuation of viruses and to that of
vaccination by attenuated microbes. Thus the problem of the mechanism
of immunity was stated.

The first theories propounded on the subject concerned the humors.
Pasteur supposed that immunity was due to the absorption, by the
vaccinating microbes, of certain nutritive substances in the humors,
which, not being renewed for some time, were missed by the microbes
afterwards introduced into the organism, which therefore could not
develop completely. Chauveau, on the other hand, thought that, in cases
of immunity, the humors contained substances which were unfavourable
to microbes. Those theories explained particular facts, but were not
applicable to the generality of cases.

Other theories,[21] whilst attributing an active part to the organism
itself, failed to account for the mechanism of immunity in general.
This was due to the fact that knowledge at that time lacked the two
essential elements, _i.e._ the modifications suffered by the organism
which was becoming immunised, and the fate of the microbes in the
refractory organism.

  [21] Naegeli, Büchner, Gravitz.

The disappearance of the microbes in the cured or refractory animal
had indeed been observed;[22] the inflammatory reaction of the organism
in the course of immunisation had been noted;[23] microbes had long
ago been observed inside the white globules of pus;[24] but, either an
erroneous interpretation was given to the facts observed, or, rather,
the links of causality between those factors failed to be established
because they were observed solely in the complicated organism of
superior beings. Humoral theories, less easy to test, preserved an
appearance of generality and were easily admitted.

  [22] Chauveau.

  [23] Büchner.

  [24] Hayem, Birsch, Hirschfeld, Kleps, Recklinghausen, Waldeyer,
       and Virchow.

Such was the state of the question when Metchnikoff approached it
from a naturalist's point of view. He knew the life of unicellular
beings and that of the lower multicellular organisms in their
complete simplicity; he knew their mode of defence by ingestion and
intracellular digestion. Having become familiar with these phenomena,
visible in the single cell, he was better able to see his way in
the complicated _milieu_ of higher beings. He was therefore able
to discover the connection between the divers factors which other
scientists had observed singly. He was able to prove that it is the
combination of these factors, _i.e._ inflammation, the ingestion of
living and virulent microbes, and their disappearance by means of
intracellular digestion which makes immunity possible. He demonstrated
that "there is but one permanent element in natural or acquired
immunity, and that is phagocytosis."

The extension and importance of this factor, applicable to the whole
animal kingdom, proved the truth and general scope of the phagocyte
doctrine of immunity.

In 1900, Metchnikoff presented to the International Congress in Paris
a complete tabulation of his researches and fought his contradictors
for the last time, after which, convinced that his deductions were
solid, he began to write a work on _Immunity in Infectious Diseases_.
In it he epitomised, as in a great harmonious chord, the results of
his researches, reaching over a period of nearly twenty years; he
affirmed and gave final expression to his doctrine of immunity, based
on the comparative study of the mechanism of that phenomenon and of
its evolution along the whole scale of living beings; he related his
controversies, analysed the objections to his doctrine, expounded the
theories of other scientists concerning immunity, and gave a general
view of the present state of the question. This book is a living
picture of a long and important part of Metchnikoff's scientific
achievements.

       *       *       *       *       *

The question of immunity is of such great importance, the mechanism
of this phenomenon and the physiology of intracellular digestion are
so complicated, that I have thought it useful to epitomise here the
exposition given of it by Metchnikoff in his book. Readers who do not
care to go further into the subject can pass over the next few pages
without hindering their comprehension of the following chapters.

Diseases affect all living beings, and the greater number of plants and
animals would cease to exist without innate or acquired immunity.

Unicellular beings are generally immune against infectious diseases,
which are rarely observed in them. Their body being almost entirely
made up of digestive protoplasm, the microbes which they absorb are
directly introduced into a noxious medium and are destroyed therein
like any other food. If the microbes are indigestible, they are
immediately rejected; hence, in the majority of cases, they cannot
become harmful.

This resistance of unicellular beings to many microbes and microbian
toxins is due not only to the intense digestive power of the cell but
also to the extreme sensitiveness which rules over the choice of food.
Owing to this protoplasmic sensitiveness (_chimiotaxis_) protozoa are
attracted towards certain microbes or substances (positive chimiotaxis)
and repelled by others (negative chimiotaxis). Thus, many ciliate
infusoria choose bacteria only for their food; they are sharply
repelled by dead infusoria, etc.

Therefore, in the _natural_ immunity of unicellular beings, two
fundamental elements may already be observed: sensitiveness and
intracellular digestion. No researches have yet been made on the
possibility of conferring on protozoa an artificial immunity against
certain pathogenic microbes and their poisons. But unicellular beings,
insensible to microbian poisons, are the reverse to many chemical
substances which, in their normal life, they have no opportunity of
ingesting.

It has been proved by experiment that, against many of those chemical
substances, an artificial immunity may be given to the protozoa by
accustoming them gradually. Very diluted solutions are added at first
to the medium in which they live and, by gradually concentrating
those solutions, an artificial immunity is conferred; the negative
chimiotaxis becomes positive, allowing the protozoa to absorb and
digest the poison, now become a food.

_Habit_ is therefore the fundamental condition of artificial
immunity; it must be that also of immunity naturally acquired. Having
accidentally digested enfeebled microbes or having suffered an attack
of disease, the unicellular being becomes accustomed to a stronger
virus and becomes immune against it. The fact that so many unicellular
beings have become thus accustomed is therefore connected with their
sensitiveness and their digestion. Accordingly, sensitiveness, habit,
and digestion are the fundamental factors of the mechanism of immunity
in protozoa; this immunity thus indisputably belongs to the category of
purely _cellular_ phenomena.

Having arrived at this conclusion, Metchnikoff thought that the same
mechanism of immunity must be found in other primitive and analogous
cells, such as the phagocytes of multicellular beings. This was
proved by a whole series of observations and by the fact that the
immunity of higher animals is connected with an intense phagocytosis.
In fact, as he ascended the scale of beings and studied their natural
and artificial immunity, he ascertained that, in all of them, the
essence of immunity, masked by the complexity of the organism, reduced
itself to the _phagocytes becoming accustomed_ to noxious agents. The
mechanism of immunity in protozoa could therefore really be compared
with that of immunity in multicellular beings.

Becoming accustomed and becoming immune are phenomena of a general
order, for they can be manifested not only by animals, but also by
plants. They, too, have to defend themselves against numerous diseases.
Lower vegetables, such as myxomycetes (beings which stand on the limit
between the animal and vegetable kingdoms), have an amoeboid phase,
in which they are but a simple heap of formless protoplasm. During that
stage of their life, myxomycete behave towards noxious agents exactly
in the same way as unicellular beings and, like them, acquire immunity
by becoming gradually accustomed.

In higher vegetables, the mechanism is different because of their
structure. The cells of nearly all plants are immobilised by rigid
membranes; therefore they cannot surround their prey, but protect
themselves by the production of tough membranes (cicatrisation) and
by the secretion of various juices. Certain of these juices (gums
and resins) become solid when exposed to the air and constitute a
sort of natural (dressing); others (essences) are antiseptic. The
secretion of these cellular juices in plants is therefore a powerful
means of defence. This defence is due to the extreme sensitiveness
of the protoplasma of vegetable cells: they react against irritation
by a defensive secretion. Vegetables, as well as unicellular beings,
can accustom themselves or become artificially accustomed to noxious
influences and acquire immunity.

As to animals, Metchnikoff had already proved long ago that they
defend themselves against morbid agents by phagocytosis, _i.e._ by
intracellular digestion. It is always to be found in cases of immunity
and is indispensable to it, on the same grounds as in unicellular
beings. The organism of multicellular animals possesses various
cells which play the part of phagocytes. There are some in the blood
and humors, as also in the divers organs and in the tissues. These
phagocytes are either mobile--leucocytes, or fixed--tissue-cells.
However, all those cells may be classed into two principal groups: the
microphages and the macrophages. Both categories of cells are capable
of digesting microbes, but it is chiefly done by the microphages,
whilst macrophages more especially digest figured elements (cells) of
animal origin and poisons. It may be said that the microphages are
vegetarians whilst the macrophages are chiefly carnivorous.

What, then, is the mechanism of phagocytic digestion?

Intracellular digestion by phagocytes is accomplished by means of
digestive ferments, similar to those of our own digestive organs. "In
both cases," says Metchnikoff, "a diastasic action is due to soluble
ferments produced by living elements. In intracellular digestion, the
diastases digest within the cells, whereas in extracellular digestion
the phenomenon takes place outside the cells, in the cavity of the
gastro-intestinal tube."

Only gradually has intracellular digestion given place to the digestion
by secreted juices. The link between these two modes is to be found
in certain transparent Invertebrates, such as the floating mollusc
_Phyllirhoë_. The nourishment is first digested in the cavity of the
digestive tube by secreted juices, and its treatment is completed
within the amoeboid cells of the cæcum.

In higher animals, the digestion of food is due to several digestive
ferments (rennet, pepsin, trypsin, enterokinase, etc.) produced by
divers organs (stomach, pancreas, intestines). The phagocytes also
manufacture several digestive ferments; their principal digestive juice
is a soluble ferment of the trypsin category, to which Metchnikoff gave
the name of _cytase_.[25]

  [25] It is also called _alexine_ or _complement_ by other writers.

To the morphological difference of the phagocytes corresponds also
a difference in the properties of their cytases, which are suited
to the digestion of this or that food. The cytases are kept within
the interior of the cells and only escape into the humors when the
phagocytes are damaged (Pfeiffer's phenomenon). This kind of ferment
does not withstand a temperature above 55° to 58° C. In natural
immunity, it plays the principal part by digesting morbid agents inside
the phagocytes like any other food. But, in artificial immunity,
other soluble ferments come into play, developed in consequence of
vaccination.

The principal of those is the _fixator_.[26] It is less sensitive
than cytasis to high temperatures and can bear a temperature of 65°
to 68° C. It is incapable, by itself, of killing and digesting, but
by _fixing_ on them, it _bites_ them, so to speak, and makes them
sensitive to the action of the phagocytic cytases, which can thus
digest them more easily.

  [26] Designated by other writers by various synonyms: preventive,
       or sensibilising substance, immunising body, amboceptor.

The _fixator_ may be compared to _enterokinase_, a special ferment in
the small intestine of higher animals which also does not by itself
digest food but which activates in a high degree the digestive power of
pancreatic ferments. However, it has the property of fixing itself on
fibrin; it is obvious that enterokinase and the fixator have the same
essential properties. This similarity again proves that the destruction
of morbid agents by the phagocytes really corresponds with actual
digestion.

It is in consequence of the digestion of vaccinal products that the
phagocytes manufacture the _fixator_. Created at the expense of a
given vaccinal substance, the _fixator_ has a specific character which
corresponds with that substance, whereas the cytase already existing
within the phagocytes never has a specific character.

_Artificial_ immunisation generally produces the formation of so
great a quantity of fixators that the phagocytes are unable to retain
them and excrete them in part in the ambient humors, _i.e._ the blood
plasma, or serum. When, afterwards, virulent morbid agents (microbes
or figured elements) are introduced into an organism which has been
immunised against them, they are at once faced, in the humors, with
_fixators_, which immediately exert a biting action on them and render
them sensitive to the action of the intracellular cytasis of the
phagocytes. The same mechanism explains the specificity of the serums
of vaccinated animals.

The quantity of specific fixators in the humors depends on the surplus
production of that ferment by the phagocytes and is not always the
same. That is why different serums are preventive in different degrees.
They are inactive if the phagocytes have not produced enough fixators
to pass any out into the humors. For a serum is only preventive when
it brings into the new organism into which it is injected a sufficient
quantity of fixators ready to sensibilise the morbid agents afterwards
introduced into the organism.

The over-production of antibodies--fixators or antitoxins--corresponds
up to a certain point with the frequency and quantity of vaccinal
injections; that is why serums are usually preventive in artificial
immunity and very rarely so in natural immunity. Through successive
inoculations, the cells become accustomed to digesting the microbes, or
figured elements, and manufacture, in consequence of that digestion,
growing quantities of fixators.

In natural conditions, on the other hand, morbid agents do not usually
penetrate into the organism in massive or repeated doses; therefore
digestion under natural conditions results in a less abundant
production of fixators which can be contained in the interior of the
phagocytes without leaking into the humors in sufficient quantities to
render the latter preventive.

It might be thought that immunity against pathogenic microbes is
accompanied by immunity against their toxins. In reality that is not
always the case, and very often the organism, now made refractory to
certain microbes, remains sensitive to their toxic products. Thus
antimicrobian immunity and antitoxic immunity constitute in most cases
two distinct properties. In order to confer antitoxic immunity recourse
must be had to vaccination by soluble poisons and toxins.

Immunity, acquired naturally, is so especially against microbes and
not against toxins, for, in nature, it is almost always by microbes
that the organism is threatened. As to _antitoxic_ immunity, it is
very probably due to the intracellular digestion of toxins by the
different macrophages. This hypothesis is supported by the experiments
quoted in the preceding chapter. During antitoxic vaccination, the
macrophages manufacture, probably at the expense of vaccinal toxins,
a certain quantity of _antitoxins_, substances which offer a great
similarity with the fixators. Like them, they are specific; they are
also produced in great quantities and excreted into the humors, which
they render antitoxic when sufficiently abundant; finally, they are
not very sensitive to high temperatures. That is why, in spite of the
impossibility of proving their origin directly, it is quite probable
that it is analogous to that of the fixators and that antitoxins are
manufactured by cellular elements, the macrophages in particular. For
it is they which absorb and digest toxins as well as soluble poisons.

This deduction is also supported by the antitoxic immunity which may be
conferred on _unicellular_ beings in which the cell alone enters into
play.

Phagocytes no doubt manufacture many other soluble ferments
corresponding with the elements which they absorb, for, in a vaccinated
organism, divers new specific properties of the serum are to be found,
such as that of agglutination, precipitation, etc. Humoral properties
may be more or less durable, in proportion as the products manufactured
by the phagocytes are more or less rapidly evacuated by the organism.

All these humoral properties, traced back to their first source, depend
upon the digestive activity of the phagocytes, since they are the
products of that digestion. In cases where it has not yet been possible
to make a direct demonstration of this, it becomes evident through
analogy and experiments pointing in that direction.

To sum up, according to Metchnikoff, "_Immunity in infectious diseases
is linked with cellular physiology, namely, with the phenomenon of
the resorption of morbid agents through intracellular digestion._
In a final analysis, the latter (as also the digestion of food
in the gastro-intestinal tube) reduces itself to phenomena of a
physico-chemical order; however, it is a real _digestion_ accomplished
by the living cell.... The study of Immunity, from a general point of
view, belongs to the subject of Digestion."

Immunity against diseases is but one of the manifestations of an
immunity on a much larger scale, always based, in final analysis, on
the sensitiveness of the living cellular protoplasm. The sensitiveness
of the nervous cells extends this phenomenon to the psychical domain.
They also are capable of becoming accustomed to external irritations of
all kinds, hence constituting a psychical immunity for the organism.
We all know that one can become accustomed to many painful or violent
sensations; and, as Metchnikoff says: "... It is very probable that
the whole gamut of Habit, starting from the unicellular beings, who
accustom themselves to live in an unsuitable medium, to cultured men
who acquire the habit of not believing in human justice, rests on one
and the same fundamental property of living matter."




                             CHAPTER XXVII

  Private sorrows--Death of Pasteur, 1895--Ill-health--Senile
  atrophies--Premature death--Orthobiosis--Syphilis--Acquisition
  of anthropoid apes.


Metchnikoff's health had suffered from the numerous emotions provoked
by the struggle in defence of the phagocyte doctrine and also from a
series of sad events. In 1893, sickness and death fell upon our family;
I lost a sister and a brother at a short interval and had myself to
undergo a serious operation. My husband nursed me night and day, as a
mother might have done, and went through the deepest anxiety on account
of post-operative complications. All this told on him all the more
that he had just endured cruel moral suffering during the experiments
on cholera mentioned above. In 1894, an agricultural crisis in Russia
influenced our material situation and gave him many worries. In the
autumn of 1895, M. Pasteur's health became worse and, soon afterwards,
he died.

This series of calamities depressed Metchnikoff, his old cardiac
trouble returned, and he again became a prey to insomnia. We spent part
of the holidays in the mountains, thinking it might do him good, but he
did not care for a prolonged rest; he was preoccupied by the thought
of his interrupted experiments and only thought of returning to the
laboratory.

In 1898, he had some disquieting symptoms of kidney trouble, a little
albumen. He consulted the celebrated German physician, von Noorden, who
found nothing serious, but this did not reassure him and he continued
to worry about himself.

Already some time previously, theoretical considerations on senile
atrophies had directed his thoughts towards old age. His reflections
now turned towards the psychological aspect of the problem; he analysed
his personal sensations and realised that he, at the age of 53, felt an
ardent desire to live. This imperious instinct for life, in spite of
the inevitable evolution towards personal death and old age, brought
his thoughts back to the disharmonies of human nature. But now,
through all his gloomy reflections, he was borne up by the unshakable
conviction that Science would succeed in correcting those disharmonies
and he continued to work with untiring energy.

He had prescribed for himself a hygienic diet, based on the idea that
the cause of his own condition and senility in general was due to
a chronic poisoning by intestinal microbes. This diet consisted in
avoiding raw food in order not to introduce noxious microbes into the
intestines, and in absorbing their useful enemies, the acid-forming
microbes of sour milk. This diet was very favourable to his health.

After he had finished his book on immunity he at last allowed himself
to pass on to the new questions which preoccupied him, _i.e._ senility
and death.

He set forth a sketch of his ideas in 1901 in a paper which he read
at Manchester (Wilde Lecture) on the "Flora of the Human Body." He
reviewed this flora and pointed out the harmful effect of the microbes,
especially those of the large intestine the toxins of which effect a
chronic poisoning of the cells of our organism and thus provoke their
gradual weakening. He then indicated the means of combating this evil,
on the one hand by stimulating the vital activity of the cells exposed
to enfeeblement, by means, for instance, of small doses of specific
cytotoxins, and, on the other hand, by direct action on intestinal
microbes. He concluded by saying that "the intestinal flora is the
principal cause of the too short duration of our life, which flickers
out before having reached its goal. Human conscience has succeeded in
making this injustice obvious; Science must now set to work to correct
it. It will succeed in doing so, and it is to be hoped that the opening
century will witness the solution of this great problem."

Metchnikoff considered that our chronic poisoning by intestinal
microbes weakens our cellular elements; he supposed that the same cause
might provoke senile phenomena, manifestly due to weakness of the
tissues.

One of the first manifestations of senility being the whitening of
hair, he began to study the mechanism of that. He had previously
observed the dominant part played by phagocytosis in all phenomena
of atrophy, and it occurred to him that it may be phagocytes which
destroy the colouring matter of hair, a substance which, in the form
of tiny granules, is enclosed within the hair cells. In fact, he
found that the whitening process is accompanied by a stimulation of
the amoeboid cells which introduce their protoplasmic prolongations
into the periphery of the hair. They absorb the coloured granules,
or pigment, and digest it, partly on the spot, partly after carrying
it into the root of the hair, often even in the connective tissue
which supports the hairy scalp. As the pigment becomes destroyed,
the hair loses its colour and whitens. The cells which devour the
pigment--pigmentophages--belong to the category of macrophages which,
in general, absorb all the enfeebled cells in the organism.

Metchnikoff was able to note similar phenomena in divers other senile
atrophies either by his own ulterior researches or by collaboration
with his pupils (MM. Salimbeni and Weinberg).

In the same way that the whitening of the hair depends on the
destruction of pigment by pigmentophages, the wrinkles of the
skin, weakness of the muscles, friability of the bones, and senile
degenerescence of divers organs are caused by the destruction of
weakened cells which do not defend themselves and thus become the prey
of the stronger and more resisting macrophages. Senility is thus no
other than a generalised atrophy. What is it that provokes it? The
answer is: The swarming microbes in our large intestine. They form the
permanent source of a slow poisoning of our organism. This fact alone
suffices to explain one of the principal causes of the enfeebling
of our tissues. It is not simultaneous in all the cells because of
their different powers of resistance. The struggle and destruction
of the weak by the strong is the cruel law of nature; therefore the
macrophages, more resisting to poisons, take advantage of the weakening
of other cells in order to devour them, and this is one of the causes
of senility.

These reflections and the biological researches which confirmed them
allowed Metchnikoff gradually to build up a philosophical doctrine,
which he expounded in 1903 in his work, _Études sur la nature humaine_.

He considered "old age" as a pathological phenomenon. He saw in it one
of the most important disharmonies of human nature, because of the fact
that neither senility nor death is accompanied by a natural instinct.
The accomplishment of every physiological function leads to satiety or
to a desire for rest; after a busy day, man feels an instinctive need
for rest and sleep. But, in his maturity, he has no desire to grow old,
and in his old age none to die. It is rare that one should aspire to
die, and nobody wishes to grow old. These facts are in contradiction
with other natural phenomena; they are all the more discordant that
they play an immense part in our psychical life.

After a general review of opinions on human nature, Metchnikoff
analysed it from the biological point of view; he revealed its discords
and concluded that it is far from being perfect. In his eyes, the
lack of harmony in the human being is an inheritance from our animal
ancestors; they have handed down to us a whole series of remains
of organs which are not only useless but even harmful in the new
conditions of human existence.

The large intestine, inherited from mammalian ancestors, holds the
first place among those noxious organs. This reservoir of food
refuse was very useful to our animal forebears in their struggle
for existence; it allowed them not to interrupt their flight whilst
pursued by their enemies. In man, whose life conditions are different,
a large intestine of that size, without offering the same advantages,
is a source of slow and continuous poisoning and a cause of premature
senility and death.

Man, after acquiring a still higher development, realised these
evils and made concentrated efforts to fight them and to soothe his
own terrors. It is for that object that the divers religious and
philosophical systems were created, in which humanity sought for
consolation. Finding none there, man turned to Science, which, at
first, neither solved his doubts nor eliminated his sufferings. But
Science provided him with rational methods of research, owing to which
he gradually progressed and conquered a series of truths, allowing him
gradually to struggle against some of his troubles and to solve some of
his problems. Science has already done much to diminish the diseases
which are among the chief scourges of humanity. It has thrown light
upon the causes of many of them and has found preventive and curative
remedies for several.

Surgery, antiseptics, serotherapy, vaccinations already yield secure
results. Hygiene and prophylaxis are in course of development, and
a vast prospect is open to them in the future. But our heaviest
burdens, senility and death, common to all, have yet scarcely been
studied. Having expounded his views on senility and proved that it is a
pathological phenomenon, Metchnikoff concluded that to struggle against
it was quite as possible as to struggle against disease.

The principal causes which bring about _premature_ senility are:
alcoholism, chronic poisoning by intestinal microbes, and infectious
diseases, headed by syphilis. Surely Science will discover efficacious
means against all these.

The strengthening of the beneficent cells in our organism; the
transformation of the wild intestinal flora into a cultivated flora, by
the introduction of useful microbes; the struggle against infectious
diseases and alcoholism--all these are workable means of fighting
pathological and premature senility.

When old age becomes physiological and no longer painful it will become
proportionate with the other epochs of our lives and cease to alarm us.
But how is the fear of death to be explained, since it is a general and
inevitable phenomenon? How is it that we have no _natural instinct_ for
death? Metchnikoff supposes that this lack of harmony in our nature
comes from the fact that death is as _premature_ as senility and
arrives before the _natural instinct for it_ has had time to develop.
This supposition is confirmed by the fact that old people who have
reached an exceptionally advanced age are often satiated with life and
feel the _need_ of death as we feel a need of sleep after a long day's
work. That is why we have a right to suppose that, when the limit of
life has been extended, owing to scientific progress, the instinct of
death will have time to develop normally and will take the place of the
fear which death provokes at the present day. Both death and old age
will become physiological and the greatest discord in our nature will
be conquered.

Our manner of life will have to be modified and directed according to
rational and scientific data if we are to run through the normal cycle
of life--_orthobiosis_. The pursuit of that goal will even influence
the basis of morals. Orthobiosis cannot be accessible to all until
knowledge, rectitude, and solidarity increase among men, and until
social conditions are kinder.

Man will then no longer be content with his natural inheritance; he
will have to intervene actively in order to correct his disharmonies.
"Even as he has modified the nature of plants and animals Man will have
to modify his own nature in order to make it more harmonious."

In order to obtain a new race, one forms an ideal in relation to the
organism to be modified. "In order to modify human nature, it is
necessary to realise what is the ideal in view, after which every
resource of which Science disposes must be taxed in order to obtain
that result. If an ideal is possible, capable of uniting men in a
sort of religion of the future, it can only be based on scientific
principles. And if it is true, as is so often affirmed, that it is
impossible to live without faith, that faith must be faith in the power
of Science."

In those words, Metchnikoff ends his book on Human Nature.

       *       *       *       *       *

The public at large and many critics did not understand the deep and
general meaning of Metchnikoff's thoughts. They reproached him with
having an insufficiently exalted ideal, for they only saw in his
doctrine the desire of postponing senility and living longer. They
did not understand that to revolt against the lack of harmony in
nature, through which all humanity has to suffer, not only physically
but morally, was to aspire to perfection. They did not consider
that, in order to attain that end, all human culture and the whole
social state would have to be modified; that this could only be done
through many virtues, intense energy, and great self-control. They
had not understood the elevation and power of an ideal which aspired
to perfect not only the direction of life but human nature itself.
They had not understood the audacious beauty of such a struggle, the
benefit conferred by the belief that the human will and the human mind
are capable of transforming Evil into Good according to a conceived
ideal!...

In the meanwhile Metchnikoff, convinced that Knowledge is Power and
that "Science alone can lead suffering Humanity into the right path,"
quietly continued his task.

       *       *       *       *       *

One of the most characteristic symptoms of old age is the hardening
of the arteries--arterio-sclerosis. He therefore especially wished to
elucidate the mechanism of that phenomenon.

Whilst many, yet unknown, factors come into play in senility, one
disease, syphilis, often provokes arterio-sclerosis, indisputably due
to a morbid agent. Metchnikoff therefore began to study this disease,
of which the origin is infectious--especially as he thought he could do
so experimentally.

Long before this, he had conceived the idea that the study of those
human diseases which cannot be transmitted to ordinary laboratory
animals might be carried out on anthropoid apes, of all animals the
nearest to man. He had spoken of it to M. Pasteur, but, at that time,
the Institute could not afford to acquire these costly animals. In
1903, at the Madrid Congress, Metchnikoff received a 5000 fr. prize
and utilised this money in the acquisition of two anthropoid apes. The
same year M. Roux won the Osiris prize of 100,000 fr. which he devoted
to the same object, and it was decided that the two together would
undertake researches on syphilis. Other donations, 30,000 fr. from the
Morosoffs of Moscow and 250 roubles from the Society of Dermatology
and Syphilography of the same city, completed the capital required to
execute the projected plan.

The following is a short sketch of the researches that were undertaken
and the results that were obtained.

The inoculation of anthropoid apes with syphilis was successful. The
chimpanzee was found to be most sensitive to the disease; it manifests
primary and secondary symptoms identical with those of man. Lower
monkeys, though less sensitive, also contract syphilis but generally
only show primary characteristic manifestations. The possibility of
rapidly provoking in apes, even of the inferior kinds, syphilitic
lesions similar to those of man has a very great importance, for it
provides a sure means of diagnosis in doubtful human cases. Owing to
the liability of apes to contract syphilis, experimental vaccination
and serotherapy could be attempted on them; but, though these
experiments were sometimes encouraging, the results obtained were not
constant enough to justify their application to man. Thus, it was found
possible to attenuate the virus by successive passages in certain lower
apes, and yet, though attenuated for the chimpanzee, it did not confer
upon him immunity against the active virus.

In 1905, Schaudinn discovered the syphilitic treponema in man. By
using this discoverer's method, the same microbe was found in apes
inoculated with human virus, which confirmed the specific character of
the treponema.

An observation was then made which was of great importance on account
of its consequences: it was ascertained that the syphilitic microbe
was absorbed by the less mobile mononuclear phagocytes and remained
localised near the entrance point long enough to allow of a local
treatment which might succeed in being curative as it had time to act
before the microbes had passed into the general circulation of the
organism. This supposition was proved to be correct by a series of
experiments on monkeys, and, in 1906, a young doctor, M. Maisonneuve,
inoculated himself with syphilis and applied the treatment with a
perfectly satisfactory result.

It might have been thought that this simple, safe, and innocuous method
would at once come into practice, but it was not so. Between opposition
on the one hand, and carelessness of the subjects themselves on the
other, this useful discovery remained for a long time without being
utilised. All the above results were obtained through experiments on
anthropoid apes, and the study of syphilis, until then purely clinical,
entered at last into the field of experimental science.

       *       *       *       *       *

Researches upon syphilis were but an interlude; Metchnikoff, returning
to his principal work, resumed the study of senility and of the
intestinal flora. During many years he applied himself to researches
concerning the part played by the latter within the organism.

He was able to confirm the deductions expounded in his _Études sur
la nature humaine_, and in 1907 he published a new work, _Essais
optimistes_, in which he developed the same ideas, amplified by the
results of his new researches, and answering the criticisms excited by
his first book.

In the _Essais optimistes_ he studied first of all the phenomena of old
age in the different grades of the scale of living beings, of which he
compared the life duration. He concluded that there was an indubitable
connection between this and the intestinal flora.

The shorter the intestine, the fewer microbes it contains and the
longer the relative duration of life. As an example, he quoted the
relatively great longevity of birds and bats. Those animals, adapted
to aerial life, have to weigh as little as possible. To that end,
they empty their intestine very frequently and this in consequence is
not used as a reservoir for alimentary refuse; as it is but little
developed, it contains a much smaller number of microbes. The longevity
of flying animals is relatively much greater than that of mammals with
a large intestine full of microbes, a constant source of slow poisoning.

After treating the question of longevity, Metchnikoff dealt with that
of death.

Living beings die, in the great majority of cases, in consequence
of diseases or accidents with an external cause; one involuntarily
wonders whether there is such a thing as "natural death," _i.e._
arising exclusively from causes due to the organism itself. A review
of known facts allowed Metchnikoff to draw the following conclusions:
unicellular inferior beings have no _natural_ death; they merely die by
accident. Their individual life is very short and comes to an end by
multiplication or division of a unit into two; there is no trace of a
_corpse_ in this loss of previous individuality.

Among superior plants, certain trees attain considerable dimensions
(dragon-tree, baobab, oak, cypress), live for centuries, and die from
external causes. Their organism presents no _internal_ necessity for
a natural death. On the other hand, a multitude of other plants have
but a short life and their natural death coincides usually with the
ripening of the seed. It has even been observed that it is possible
to retard the death of a plant by preventing it from fructifying. For
instance, lawns made up of grass mown before it runs to seed remain
green and living whilst grass allowed to flower and bear seed becomes
yellow and dries up. It is a well-known fact that fruits and seeds are
frequently poisonous. Therefore Metchnikoff supposed that the death of
the plant may be due to an auto-intoxication by poisons manufactured
by it in order to defend its seeds and ensure the next generation;
in Nature, the individual does not count, but the species. Once the
survival of this is ensured the individual may disappear.

A similar phenomenon of auto-intoxication is manifested by lower
vegetables, yeasts, and microbes. Pasteur, who discovered the microbe
of lactic fermentation, found that this micro-organism, which itself
produces lactic acid, perishes because of the over-production of this
substance. Yeasts, again, cannot bear an excess of alcohol, their own
product. Thus the vegetable kingdom offers us examples of the absence
of natural death as well as examples of a natural death due to an
auto-intoxication of the organism.

In the animal kingdom examples of natural death are also to be found,
but only very exceptionally. Those examples are provided by Rotifera
(inferior worms) and by Ephemeridæ. Their adult life is reduced to the
sexual act, almost immediately followed by death without an external
cause. Their life is so short that they do not even feed and lack
developed buccal organs. That in itself constitutes an organic cause of
inevitable, _i.e._ natural, death.

Among human beings natural death is extremely rare. It sometimes
occurs in very old people, under the shape of a peaceful last sleep.
The likeness it bears to sleep is so striking that Metchnikoff thought
himself authorised to form the following hypothesis concerning the
analogy in their mechanism.

According to a theory of Preyer's, fatigue and sleep are due to a
periodical auto-intoxication set up by the products of the vital
activity of our organism. These products are destroyed by oxidation
during sleep, after which fatigue disappears and awakening comes.
According to Metchnikoff it may be that the mechanism of natural death
also consists in an auto-intoxication by the progressive accumulation
of toxic products during the whole of life. The analogy between sleep
and natural death allows the supposition that, as before going to sleep
an instinctive desire for rest is felt, in the same way _natural_
death must be preceded by an instinctive desire to die. Moreover,
this is confirmed by concrete examples. Thus that of an old woman
of ninety-three who expressed that desire in the following terms to
her great-nephew: "If ever you reach my age, you will see that death
becomes desired just like sleep." The same thought had been expressed
by the biblical patriarchs who fell asleep satiated with life.

When, owing to the progress of Science, men reach the development of
the instinct of death, they will look upon Death with the same calm as
do very old people, and it will cease to be one of the principal causes
of pessimism. It is for that reason that we must learn to prolong life
and to allow all men to realise their complete and natural vital cycle,
thus ensuring their moral balance.

Psychological observations allowed Metchnikoff to conclude that
pessimism is much more frequent in youth than in maturity or in old
age. He attributes this to the gradual development of the _vital
instinct_ which is only completely manifested in middle age. Man then
begins to appreciate life; made wiser by experience, he demands less
and is therefore better balanced.

Metchnikoff proffers examples in support of his theory. He analyses the
psychic evolution of Goethe as reflected in his _Faust_ and describes
that of "an intimate friend." These examples prove that natural
psychological evolution already leads to a relative optimism. But, as
long as senility is pathological and death premature, the apprehension
that they inspire antagonises the normal evolution of optimism. A
victory over those present evils will direct the normal course of life
in the right way; one normal active period will succeed another; the
accomplishment of individual and social functions corresponding with
each period will become realisable; the death instinct will have time
to develop, and Man, having been through his normal vital cycle, will
sink, peacefully and without fear, into eternal sleep.




                            CHAPTER XXVIII

  Researches on intestinal flora--Sour milk.


The problem of our intestinal flora is so vast and so difficult that it
demands years of research. Numerous facts had already been accumulated
by Science on this subject, but it was still far from being elucidated.

Certain scientists affirmed that microbes favour digestion by
decomposing food residues in the intestine and are therefore not
merely useful, but necessary to the organism. Others entertained a
diametrically opposed opinion. The first thing, therefore, was to know
which of the two opinions was founded on fact. Metchnikoff studied
the case of the bat, in which the digestive tube is short and the
large bowel not even differentiated. As he had supposed, _a priori_,
in this animal, whose life duration is relatively long, the intestine
contains few or no micro-organisms, which proves that digestion can
be accomplished without their intermediary. Moreover, this was before
long amply confirmed by the researches of MM. Cohendy, Wollman, and
other scientists who succeeded in bringing up chickens and tadpoles in
conditions of absolute sterility.

Having acquired the conviction that microbes are not indispensable to
digestion, Metchnikoff studied the part they play in the organism. It
is universally admitted that the products of putrefaction are toxic,
and he enquired whether the intestine sheltered putrefying microbes.
This question had not yet been solved; certain bacteriologists
thought that little or no putrefaction exists in a normal intestine.
Metchnikoff ascertained through systematic researches that the
intestinal flora includes several kinds of putrefying microbes which
secrete highly toxic products.

With his pupils and collaborators, MM. Berthelot and Wollman, he
carried out a series of experiments which established the fact that
this intoxication is due to poisons of the aromatic group, such
as phenols and indols. With these substances, they succeeded in
artificially provoking arterio-sclerosis in the organs of animals,
and also other modifications similar to those which are observed
in senility. Having proved that putrefying microbes provoke the
intoxication of the tissues, Metchnikoff set to work to find a means of
struggling against those microbes.

It was known that they could only live in an alkaline medium which
is precisely that of the intestinal juices. Metchnikoff thought that
if means were found to render the intestinal contents acid, without
harm being done to the organism, the putrefying microbes might thus be
destroyed. It had been known for a long time that sour milk does not
suffer putrefaction, that being prevented by the acid fermentation. The
lactic microbes of this fermentation must therefore be antagonistic to
the putrefying microbes. He drew a conclusion in favour of the utility
of sour milk, containing acid-producing microbes; once introduced
into the intestine, these should prevent the breeding of the noxious
microbes which require an alkaline medium.

His hypothesis seemed confirmed by the fact that populations who feed
almost exclusively on curded milk live a very long time. In Bulgaria,
for instance, whole villages, thus fed, are known for the longevity
of their inhabitants. Starting from these considerations, he made
experiments upon himself and systematically introduced into his diet
sour milk carefully prepared with pure cultures of certain lactic
bacilli. His health was benefited by it, and his friends followed
his example. Certain doctors recommended sour milk, the use of which
gradually spread as a hygienic food. Metchnikoff considered the result
acquired as a first step towards the artificial transformation of the
wild intestinal flora into a cultivated and useful flora.

Unfortunately, the study of the intestinal flora is extremely
complicated because of the innumerable species of micro-organisms and
the extreme difficulty of disentangling the many influences which
cross each other. He therefore considered collective researches as
indispensable, the life and science of one man being insufficient
to solve so vast a problem. Up to a certain point he succeeded in
realising this scientific collaboration within his own laboratory.




                             CHAPTER XXIX

  The Nobel Prize--Journey to Sweden and to Russia--A day with Léon
  Tolstoï.


In 1908 Metchnikoff received the Nobel Prize, together with Ehrlich,
for his researches on immunity. According to the statutes of that
prize, the laureate is invited to give a lecture in Stockholm.
Metchnikoff chose for his theme the "present state of the question
of immunity in infectious diseases," and, in the spring of 1909, we
went to Sweden and thence to Russia. The whole journey was a series
of fêtes and receptions in his honour. He was touched and grateful at
this welcome, but with his usual humour, declared that it was the Nobel
Prize which, like a magic wand, had revealed to the public the value of
his researches.

We only stopped for a short time at Stockholm, where the kindest
hospitality was shown to Metchnikoff. Sweden made an unforgettable
impression upon us. Her deep, dark waters, wild rocks, and sombre
pines make of it a land of legends. Elie was impressed not only by
Nature in Scandinavia but also by Scandinavian Art, which reproduces
it admirably. He was specially pleased with Lilienfiorse's pictures,
representing animals against a background at the same time real and
legendary.

We went to Russia by way of the Baltic. The nights at that time were
"white," and rocky islands covered with pines emerged from the sea
like ghosts, in the mysterious silvery midnight light; the impression
was fairy-like.

A warm welcome awaited Metchnikoff in Russia. At Petersburg, as in
Moscow, he was received with cordial and enthusiastic sympathy not
only by scientific and medical societies, but by all the intellectual
youth of those cities. This warm reception contributed to efface the
bitterness sometimes aroused in him by distant recollections of the
reasons which caused him to leave his native country.

During our stay in Russia we made the acquaintance of our great writer,
Léon Tolstoï. We spent a day with him in his estate, Iasnaïa Paliana,
and the day left a lifelong impression upon us.

It was at dawn that we reached the little railway station where a
carriage had come to meet us. It had been raining in the night and now,
in the first morning light, everything shone with dew. We were excited
by the sight of the Russian country, cool meadows, forest, fields, all
that simple landscape that we had not seen for so long, and we were
also greatly moved at the idea of meeting Tolstoï.

The village appeared in the distance and, a little way apart, the wide
open entrance gate of the old park of Iasnaïa Paliana. We entered a
long shady avenue leading to the home of Tolstoï. The spring was at its
best, flowers and perfumes everywhere. The house and the old park had
the poetic charm of the ancient "nests of nobility" in Russia.

Tolstoï's daughter greeted us on the steps; her kindly simplicity at
once put us at our ease. We had hardly entered the vestibule when we
saw Léon Tolstoï himself coming down the stairs with a brisk step.
We knew him at once, though he seemed to us different from all his
portraits. We were first of all struck by his eyes, deep, piercing, and
yet as clear as those of a child. He had nothing of that hardness and
severity that one is accustomed to see in his portraits; his features,
too, seemed to us much finer and more idealised. He looked straight
into our eyes as if he wished to read the depths of our souls. But we
were at once reassured by the kind and benevolent expression of his
whole face. He looked strong and healthy and did not seem old, but
full of inner life. After the first words of welcome, he said to us,
"You resemble each other; that happens after living happily together
for a long time." He questioned us concerning our journey and on the
impression made upon us by Russia after our long absence; then he said
he had to finish his morning task.

His daughter and son took us for a walk through the park and the
village, and the friendly words they exchanged with the peasants
indicated excellent relations between the villagers and the people of
the château. As soon as we came in, Léon Tolstoï reappeared, declaring
that he gave himself holiday for the day. He questioned Metchnikoff on
his researches, on the present state of hygiene, and on the application
of scientific discoveries. He listened attentively and with visible
interest. At the end of the conversation he declared that it was quite
erroneously that he was thought to be hostile to Science, and that
he only denounced pseudo-science, which has nothing to do with human
welfare. "In reality," he said, "you and I are aiming towards the same
goal by different lines."

All his words were impregnated with a deep love for, and an ardent
desire to serve, humanity. Literature and Art were mentioned; Tolstoï
said that he was now so far from it all that he had even forgotten some
of his own works and appreciated them much less than his writings on
spiritual questions. He thought that sometimes beauty of form acted at
the expense of the moral bearing of the subject. To the objection that
Art embellishes Life, he answered that it has some value in that it
serves as a link between men and makes them purer, but that its moral
importance surpasses its æsthetic value by a great deal.

He related that he had conceived a new work on the social movement in
Russia and, _à propos_ of that, the conversation fell upon political
reprisals. The subject of deportations, prisons, and executions was
visibly painful to him; his eyes, now sad and suffering, revealed his
vibrating soul.

On the agrarian question, he was in favour of the nationalisation of
land, and showed great enthusiasm for Henry George. He thought the
suppression of the commune in Russia a great mistake. Metchnikoff
explained to him that his personal observations in Little Russia
spoke, on the contrary, in favour of individual property, which gave
better agricultural results. Tolstoï manifested perfect tolerance,
and conversation flowed on peacefully concerning various subjects. In
everything he said the beauty and elevation of his soul was perceptible.

After lunch he desired to have a serious conversation with Metchnikoff
and took him out driving, he himself holding the reins. On the way he
returned to the question of Science. He thought that humanity was so
overwhelmed with misery and had so many urgent questions to solve that
work ought to be turned in that direction, and that we had no right to
busy ourselves with abstract questions unrelated to life. "What good
can it do man to have a notion of the weight and dimensions of the
planet Mars?" he said.

Metchnikoff answered that theory is much nearer to life than it seems,
and that many benefits have been acquired for humanity by scientific
observations of an abstract order. Thus, the discovery of the great
unchanging laws of Nature give to Man the consciousness of being
submitted to logical laws instead of an arbitrary force, and that is a
benefit. When microbes were discovered, their part in human life was
not suspected, and yet this discovery was afterwards of the greatest
service to human welfare since it enabled man to fight against disease.

On the way back, Tolstoï gave his place to his son and himself returned
on horseback, an exercise in which he indulged almost daily, in spite
of the approach of his eighty years. He still rode splendidly, sitting
quite upright, and seemed even younger than before.

After that he went to take a little rest, whilst Countess Tolstoï gave
us immense pleasure by reading to us two yet unpublished works by her
husband, the charming story _After the Ball_ and the tragic _Sergius
the Monk_.

In the late afternoon a friend of our host, an accomplished musician,
sat at the piano and played some Chopin. In the spring twilight the
charm of that music filled us with emotion. Léon Tolstoï, seated in an
armchair, listened; the lyrical beauty of the sound sank deeper and
deeper into his soul, his eyes became veiled with tears, he leant his
forehead on his hand and remained motionless. Metchnikoff also was
deeply moved, and the effect of music on two such men, the pleasure
that it gave them, was the strongest plea in favour of pure Art.

"I do not know what takes place in my mind when I listen to Chopin,"
said Tolstoï a few moments later, after the closing sounds had
vanished, "Chopin and Mozart move me to the depths. What lyrism! what
purity!" Metchnikoff liked Mozart and Beethoven, but Tolstoï thought
Beethoven too complicated. As to Wagner and modern music, they both
agreed about it, thinking it unintelligible and lacking harmony and
simplicity.

Around the tea-table conversation turned on senility, and Metchnikoff
developed his theory of the discords of human nature. He illustrated
his affirmations by the example of Goethe's _Faust_, who, according to
him, formed the best picture of the evolution of human phases. To his
mind the second part of _Faust_ is but an allegory of the disharmonies
of old age. It is a striking picture of the dramatic contest between
the yet ardent and juvenile feelings of old Goethe and his physical
senility. Tolstoï seemed interested by this interpretation and said he
would read the second part of _Faust_ over again, but that he himself
would never offer an example of a similar lack of harmony. _À propos_
of Metchnikoff's theory, according to which the fear of death exists
because Death itself is premature, Tolstoï affirmed that he had no fear
of death, but added, laughingly, that he would nevertheless try to
reach the age of 100 in order to please Elie.

Our train only left late in the night, and, until we started, the
conversation never ceased to be animated. In every one of his words
Tolstoï's exalted soul was perceptible, a soul in which there was room
but for preoccupations of a spiritual order. He would have given the
impression of floating above the earth if his ardent and compassionate
heart had not constantly brought him back to the miseries and faults of
human beings. The atmosphere around him was pure and vivifying as on
high peaks, and the place seemed sanctified by his presence.

That interview had been a meeting of two superior minds, two exalted
souls, but how different! The one, scientific and rational, always
leaning on solid facts in order to soar and to spread his wings in the
highest spheres of thought; the other an artist and a mystic, rising
through intuition to the same spiritual heights; both pursuing the same
goal of human perfection and happiness, but going along such different
roads....

As we took leave of him, Léon Tolstoï said, "Not farewell, but _au
revoir_!" And as we sat in the carriage and started to go, he appeared
in a lighted window, as in an aureola, waving his hand, "Au revoir,
au revoir!" he repeated for the last time.... The night was calm and
beautiful under the immensity of the starry vault, and its greatness
was confounded in our souls with the greatness of Léon Tolstoï.




                              CHAPTER XXX

  Intestinal flora--Infantile cholera--Typhoid fever--Articles on
  popular Science.


When he returned home, Metchnikoff immediately resumed his work. He
continued, with his collaborators, researches on the normal intestinal
flora and on the microbian poisons which provoke arterio-sclerosis.

They were able to ascertain that certain microbes of the intestinal
flora, such as the _bacillus coli_ and _Welch's bacillus_, produce
poisons (phenol and indol) which are reabsorbed by the _normal_
intestinal walls and which provoke arterio-sclerosis and other lesions
of the organs. A part of those poisons is eliminated by the urine,
and the quantity found therein allows one to estimate the quantity
contained in the organism. An exclusively vegetarian or carnivorous
diet increases its production, while a mixed diet reduces it. During
the rest of his life Metchnikoff made systematic and periodical
analysis of his own urine in correlation with his diet.

From certain facts and certain experiments he concluded that the
reciprocal influence of microbes might be utilised to attenuate or to
eliminate the noxious action of some of them. Thus, by cultivating
the lactic bacillus in the presence of those microbes which produce
poisons belonging to the aromatic group, the decrease in quantity
and even the disappearance of phenol and indol is observed. All those
facts confirmed anterior results which Metchnikoff had obtained, and
indicated the route to be followed in his struggle against those toxins
which gradually poison the organism and induce premature senility.

Having thus elucidated certain questions concerning the part played by
microbes in a normal organism, he studied the pathogenic intestinal
flora. He began by infantile cholera because this question is
simplified by the fact that new-born children are fed exclusively
on milk. It was then believed by practitioners that this intestinal
disease of infants came from their mode of feeding, from summer heat,
and other external influences. Metchnikoff, however, succeeded in
demonstrating that the contents of the intestines of infants suffering
from "cholera" always included a special kind of microbe, the _B.
proteus_; he was also able to give the disease to young anthropoid
apes by making them ingest food soiled by the intestinal contents of
sick infants, thus establishing the infectious character of infantile
cholera.

He then attacked another intestinal disease, typhoid fever, of which
the microbe (_Eberth's bacillus_) had been known for some time, but
had not been studied experimentally, ordinary laboratory animals
being refractory. Metchnikoff had again recourse to anthropoids, and
succeeded in infecting a chimpanzee by making him eat food soiled by
the intestinal contents of a typhoid patient.

With the collaboration of Dr. Besredka, he undertook a series of
experiments on anthropoid apes and on macaques. The former alone took
typical typhoid fever, similar to that of man. It could be given them
by pure cultures of Eberth's bacillus, which definitely confirmed the
specificity of that microbe.

Antityphoid vaccination by means of killed bacilli not being at that
time either safe or durable, Metchnikoff advised measures of simple
preventive hygiene: the use of cooked food, great personal cleanliness,
cleanliness of streets and dwellings, and the destruction of insects,
especially flies, which often infect food. In order to popularise these
notions, he wrote a series of articles in newspapers. Later, several
scientists found efficacious means of vaccination against typhoid fever.

In 1912 Metchnikoff, in collaboration with Dr. Besredka (the author of
the antityphoid vaccination method by means of sensitised bacilli),
demonstrated on anthropoid apes that antityphoid vaccination by living
sensitised microbes is certain, and that it presents no danger of
diffusing the disease, for these microbes, harmless to the vaccinated
individual, cannot prove a source of danger for his entourage, since
they are phagocyted at the very place where they are inoculated.

Metchnikoff always considered that it was very useful to keep the
public at large informed of the results acquired by Science, because
"it is only by becoming a part of daily life that measures of hygiene
and prophylaxis will have efficacious results." He therefore lost no
opportunity of spreading scientific principles and facts. In 1908 he
had given in Berlin a lecture on "The Curative Forces of the Organism."
In a Russian review, the _Messenger of Europe_, he developed the
same subject and included an epitome of his lecture in Stockholm
on immunity. In that article he expounded the phagocyte theory of
immunity. Among concrete examples of its application, he quoted the
indications concerning the evolution of an infectious disease provided
by the quantity of leucocytes in the blood, and the process employed
by certain surgeons to diminish the danger of infection during an
operation: just as, in case of an enemy menace, the Government mobilise
an army, certain surgeons employ divers means to attract an army of
phagocytes and to stimulate their activity in case any microbes should
penetrate into the wound.

In 1909 he gave another lecture at Stuttgart, "A Conception of
Nature and of Medical Science," in which he summed up his two works
_Études sur la nature humaine_ and _Essais optimistes_. The title
of this lecture was intended to emphasise his view of human nature,
according to which "Man, as he appeared on the earth, is an animal and
pathological being belonging to the realm of medicine." But he ended
his paper by the same optimistic thought which illumines the whole
philosophy of his later years. "With the help of Science, Man can
correct the imperfections of his nature."

He unveiled these imperfections and the ills which proceed from them,
not only from a love of truth or scientific honesty, but always with
the object of finding means to combat them. He never allowed sight to
be lost of the fact that Science lights up the tortuous and painful
path which leads to an issue that suffering humanity will find by
gradually widening the limits of knowledge with the help of Work and of
Will.

Thus all his writings offer us encouragement and support.




                             CHAPTER XXXI

  A bacteriological expedition to the Kalmuk steppes, 1911.


During his preceding journeys in the Kalmuk steppes, Metchnikoff had
often heard it said that tuberculosis was almost unknown there, but
that the Kalmuks took it very easily when brought into contact with
foreigners. As all means of combating this disease had hitherto given
very unsatisfactory results, Metchnikoff thought that researches should
be started along a new path. He had long thought that observations on
the extreme liability of Kalmuks to tuberculosis might perhaps provide
some new data. But the study of the question necessitated a very
distant journey which he now at last had the opportunity of realising.

According to Metchnikoff's hypothesis, a _natural_ vaccination
takes place among us against tuberculosis which would explain the
resistance of the majority of human beings in spite of the enormous
diffusion of the disease. He concluded that some attenuated breeds of
microbes become introduced into our organism during our childhood,
thus vaccinating us against the virulent tuberculous bacillus. This
supposition seemed to him plausible, for he had long ago found that
some micro-organisms (Cienkovsky's bacillus, the cholera bacillus,
etc.) become modified in different environment and conditions, both
in form and in virulence. He had described this phenomenon in 1888
in a memoir entitled _Pleomorphism of Microbes_. His hypothesis would
explain the liability of the Kalmuks, since, if no tuberculous bacilli
existed in the steppes, the inhabitants could not acquire a natural
vaccination. When placed in an environment which was not free from
tuberculosis, they became infected very easily, being in no wise
prepared for the struggle against the virus.

The expedition to the Kalmuk country was therefore planned in order to
ascertain whether tuberculosis was really absent from the steppes. This
could easily be done by Pirquet's test,[27] which at the same time would
show whether the number of Kalmuks infected increased from the centre
to the outer limit of the steppes and corresponded with the greater
degree of contact with the surrounding population. If the enquiry
confirmed the hypothesis, there would remain to be seen which microbes
might best be used as vaccines.

  [27] A cutaneous scarification by tuberculin which provokes local
       inflammatory redness on the scarified point in tuberculous
       subjects only.

The expedition was also intended to elucidate a few questions on the
etiology of endemic plague in the Kirghiz steppes. When this intention
became known, the Russian authorities desired to add to it a local
mission on the study of plague epidemics in the steppes. Metchnikoff,
who was chiefly concerned with the question of tuberculosis, was only
able to draw up a plan of work for the Russian mission and to start it
going in one of the plague centres.

The Pasteur Institute expeditionary party comprised, besides
Metchnikoff, MM. Burnet, Salimbeni, and Iamanouchi. They were joined at
Moscow by Drs. Tarassevitch and Choukevitch, and at Astrakhan by the
physicians of the Russian plague mission. The Institut Pasteur party
left Paris on May 14, 1911, full of spirits; Metchnikoff, eager to make
the journey pleasant for his companions, was doing the honours of his
country to the best of his ability; he fully succeeded, owing to the
warm welcome and liberal hospitality which they received in Russia,
where every one tried to contribute not only to the success of the
expedition but to the comfort and pleasure of its members. The latter,
indeed, preserved a most pleasant recollection of this journey, and, in
later years, always spoke of it with pleasure.

Navigation on the Volga from Nijni Novgorod to Astrakhan was full of
peculiar charm. That five days' journey was one of the rare periods
of complete rest in Metchnikoff's life. He indulged in the _dolce far
niente_ as he watched the peaceful landscape on the passing banks. The
Volga, then in flood, covered immense spaces. Here and there, whole
forests emerged from the river which reflected them as in an enchanted
dream. From time to time, little isolated villages appeared with the
gilt cupola of a church or a monastery, then meadows, forests, steep
cliffs, or gentle slopes down to the river. What poetry, what grandeur
in simplicity! As in a kaleidoscope, types of varied populations and
pictures of local customs followed upon each other.

Along the banks now and then were seen processions of pilgrims. Their
humble, gray, stooping figures breathed deep faith and resignation.
Sometimes popular songs arose from the Volga, sad, expressive,
soul-penetrating chants.

This contemplative quietude was only interrupted by stations in the
ports of large towns where deputations of the educated inhabitants came
to wish the mission welcome. These functions had a cordial and touching
character, for it was obvious that such enthusiastic demonstrations had
for their source a sincere cult for the knowledge whose representatives
were being fêted; it was touching to see such a living ideal in this
distant and oppressed land.

At Tsaritsine, several Kirghiz embarked on our boat in order to go to
a large fair which the inhabitants of the steppes attended in numbers.
Metchnikoff thought this was a unique opportunity to learn whether
there were any carriers of the plague bacillus among those many natives
coming from all parts of the steppes. He therefore decided that those
members of the expedition who had come to study plague would go to the
fair with the Kirghiz, whilst he, with the rest of the expedition,
would make observations on the Kalmuks of the Astrakhan region.

A most hospitable welcome awaited us there; people vied with each other
in their efforts to assist the expedition. The Governor-General of
Astrakhan had ordered all preparations to be made, and the mission was
provided not only with necessaries but with comforts which did much to
alleviate the fatigue of the long journey.

Whilst waiting for our companions, we had time to verify several
diagnostical reactions, the Kalmuks lending themselves willingly to the
operation. We heard later that they thought they were being vaccinated
against small-pox, a disease much feared in the steppes.

As soon as the plague mission arrived, we started towards the Kirghiz
steppes, for there was a plague centre north of the Caspian Sea. When
we were out at sea, an intense north wind began to blow the waves away
from the Kirghiz bank, and soon the depth lessened to such an extent
that we could make no progress. The sailors were perpetually making
soundings, and their repeated cries of "Two and a half feet!" became
a regular nightmare. The situation seemed critical, and returning to
Astrakhan was suggested; an idea which infuriated Metchnikoff; he would
not hear of it. At last, after several incidents we reached the Kirghiz
bank, the crossing having lasted three days instead of the usual
twenty-three hours.

As we arrived, we could see from afar a sort of Valkyries' ride of
natives clad in brilliant colours and riding up at full gallop with
wild cries and exclamations. Before us spread a barren and sandy
steppe, producing the sad impression of a land forsaken by God and
man. How could life be possible there? But gradually, as we became
captivated by the charm of the boundless space, the purity of the air,
the harmonious colouring and the scent of wild heliotrope and wormwood
which alone can grow in those sands, we began to understand that it was
not only possible to live in those steppes, but also to love them.

The plague centre stood among sandy hills with low-growing grass; the
summit of one of them was black with charred remains of burnt objects;
the corpses were buried in the same place. Only a few wretched forsaken
hovels remained. In order to throw light upon endemic plague in the
steppes, it was first of all necessary to ascertain whether the plague
microbes remained alive for some time in places where the scourge had
raged; if they were preserved in dead bodies which had been singed
rather than burnt; if the worms, insects, rodents, and domestic animals
on the spot were or were not carriers of the plague microbe, and could
or could not transmit it to a distance from the initial focus.

After organising a small emergency laboratory, the corpses were
exhumed, and Dr. Salimbeni made a post-mortem examination. These
corpses, having been in the ground for three months, were in a state of
advanced decomposition and contained no living microbes.

Having set the work of the plague mission going, Metchnikoff parted
from it in order to accomplish the projected investigations on
tuberculosis in the Kalmuk steppes. He made a very solemn entry into
these steppes; a Kalmuk deputation welcomed the mission and presented
Metchnikoff with a bronze Buddha.

The aspect of those natives is sad and humble, their movements are
slow, their eyes dull. In this they contrast with their neighbours,
the quick and intelligent Kirghiz, and one reason for it is that the
latter, being Moslems, absorb no alcohol, while the Kalmuks consume
fermented milk (alcoholic fermentation) which poisons them slightly but
continuously; this observation had already been made by Metchnikoff at
the time of his previous visit.

The Kalmuks live in tents covered with coarse felt; they transport
these dwellings on camels from one place to another when their herds
of sheep or horses have consumed the scanty pasture grass around the
camp. There is no attempt at cultivation, and the steppes become more
and more barren as the pastures become exhausted. In order to remedy
this evil, the Russian administration has begun various experimental
plantations. In some places the steppes are covered with small tamarisk
bushes or with silky grass, but, as a rule, the chief growth is of
silver wormwood. The monotony is not so great as one might think, for
the steppes, like a mirror, reflect all the divers light-changes, and
wonderful natural phenomena take place there. During the great heat,
mirages are to be seen in the distance--a river, lakes, reed-grown
shores; sometimes a sand-storm supervenes, more infernal than
fairy-like, called here "smertch." The wind raises the sand in tongues
of flames or in funnels running up to the sky with giddy rapidity.
Gradually, all the separate turmoils join in a gigantic wall of sand,
advancing in an orgy of movement; the heavy clouds fall towards the
ground, the sand rushes upwards, everything becomes confounded in
darkness and chaos.

One feels so entirely in the power of natural forces that the fatalism
of the poor inhabitants of the land is easily understood. The Kalmuks,
primitive and nomadic, produce the impression of ghosts from distant
centuries.

Metchnikoff noticed that since his last visit in 1874, fatal influences
had worked havoc on the population. Four scourges, all of them coming
from outside, are destroying the Kalmuks: syphilis, alcoholism,
tuberculosis, and the Russians who are constantly pushing them back.
Those poor people realise the fate which is awaiting them, and resign
themselves like a sick man who knows his sickness to be incurable.

The spiritual life of the Kalmuks reduces itself to their religious
cult. There are many Buddhist convents where children are being brought
up for a monastic life. Religious rites are performed by priests
dressed in purple and brilliant yellow; for the uninitiated, their
part consists in unrolling interminable bands on which prayers are
inscribed, and in executing a religious music which seemed a mixture
of a camel's grunt, a dog's howling, and an infinitely sad plaint. Of
the pure cult of Buddha, nothing seems to remain but an empty form.
However, there is a convent in the steppes--Tshori--a sort of religious
academy, where an effort is being made to restore the cult to the
original level of Buddhist doctrines.

Whilst gathering observations on tuberculosis, we traversed the steppes
in a north-easterly direction as far as Sarepta. This town seemed like
a civilised centre after the steppes, where the conditions of life were
somewhat hard in spite of the cordial reception accorded us everywhere.
The food, consisting solely in tinned goods and mutton, had caused
intestinal trouble in nearly all the members of the expedition; on the
other hand, we were greatly incommoded by the heat, lack of water, and
abundance of insects of all kinds.

In spite of all, Metchnikoff had hitherto borne the journey fairly
well. However, since we left Moscow he had had frequent cardiac
intermittence, accompanied sometimes by sharp pains along the sternum.
But the stay at Sarepta especially tried his health; the heat reached
35° C. (95° F.) in the shade and 52° C. (about 125° F.) in the sun; in
the evening the windows could not be opened because of the mosquitoes.
Metchnikoff, who had shown so much endurance, now became weak, drowsy,
and nervous; he attributed his condition to the excessive heat. Yet
he could not leave Sarepta, for all the members of both branches of
the mission had agreed to meet there in order to sum up the results of
their observations.

The researches of the expedition for the study of plague were not
finished, and the Russian mission had agreed to complete them. So far,
it was established that neither the corpses--after a certain time--nor
the ground, nor the surrounding animals contained any plague microbes,
and no carriers had been found among the Kirghiz population.

The data gathered among the Kalmuk population justified Metchnikoff's
hypothesis. In the centre of the steppes, where the Kalmuks were still
isolated, tuberculosis was completely unknown; diagnosis reactions
were negative. They became positive more and more frequently as we
came nearer the periphery of the steppes and the Russian population.
The extreme sensitiveness of the Kalmuks must therefore depend on the
fact that they have suffered no natural vaccination in the steppes,
which would support the idea that some natural vaccine exists amongst
us. Metchnikoff therefore concluded that he might direct ulterior
researches towards the quest of natural tuberculous vaccines. Such were
the scientific results of the expedition.

Apart from that, the journey to Russia had a strong personal influence
on Metchnikoff. He had formerly left his country under the impression
of the fatal error committed by the revolutionaries in killing
Alexander II., an error which had led to a protracted reaction. He had
therefore remained very sceptical concerning the Russian revolutionary
movement; he thought that the necessary reforms might come from a
Government evolution. But, during his sojourn in Russia, he was able
to appreciate events which modified his ideas to a great extent. He
was impressed by the contrast between the progressive aspirations of
the "intellectuals" and the inertia or noxious activity of the rulers.
The policy of Casso, the Minister of Public Instruction, who ordered
regular raids in the universities, the persecution of Poles and Jews,
the encouragement of the "black band" obscurantism, giving plenary
powers to creatures of darkness like Rasputin and his peers, all these
things excited indignation in a man who placed the free development of
human culture above everything.

He thus ceased to count upon the progressive evolution of a Government
which was incapable of solving the complicated problems of Russian
life, and henceforward thought that those problems would be solved by
the "intellectuals" apart from the Government and in opposition to it.




                             CHAPTER XXXII

  Further researches on the intestinal flora--_Forty Years' Search for
  a Rational Conception of Life._


Since Metchnikoff had conceived the idea that a considerable part was
played in human life by the intestinal flora, his thoughts had centred
around a study which he thought profitable: that of the influence of
intestinal microbes on the normal and on the pathological organism.

So, on his return from Russia, he took advantage of the fact that an
epidemic of infantile cholera had broken out in order to continue his
former investigations of that disease. The numerous cases which he
thus studied allowed him finally to establish the specific part of the
_B. proteus_ as well as the similarity between infantile cholera and
Asiatic cholera. This time he succeeded in contaminating, not only
young anthropoid apes, but also new-born rabbits, and that not only
through sick children's excreta, but by pure cultures of the _proteus_,
which eliminated every doubt of the specificity of this microbe.

Metchnikoff explained the contamination of children exclusively
breast-fed, either by the presence of a carrier personally refractory,
among the entourage, or by the transport of dirt, by means of flies,
on the objects which infants so readily put into their mouths.
He therefore advised preventive means of absolute hygiene and
cleanliness, especially where suckling infants are concerned.

During the year 1912, he studied the intestinal flora and the influence
of divers food diets. He experimented upon the rat, an omnivorous
animal whose mode of feeding resembles that of man. The rats were
divided into three lots, of which one was kept to a meat diet, another
to a vegetarian régime, and the third to a mixture of both. The meat
diet was least favourable, and the best results obtained by the mixed
food.

These observations led Metchnikoff to the study of other problems
intimately connected with the same question.

He undertook a series of researches in collaboration with his pupils,
MM. Berthelot and Wollman, on the conditions which cause the diminution
within the organism of the toxic products of intestinal microbes. They
found that the quantity of these products was very small in those
animals which feed on vegetable or fruit containing much sugar, such
as carrots, beetroot, dates, etc. This is explained by the fact that
the products of the decomposition of sugar are acids which prevent the
development of putrefying microbes. But the sugar, rapidly absorbed by
the walls of the small intestine, only reaches the large intestine in a
much reduced quantity, for it is only up to a certain point during its
journey that the cellulose of vegetables, rich in sugar, protects that
substance. The question, therefore, was to find the means of making
it reach the large intestine in greater quantities. In the intestine
of a normal dog, an innocuous microbe was found, the _Glycobacter
peptonicus_, which decomposes starch into sugar.

Metchnikoff made some laboratory animals ingest this microbe together
with food, and ascertained that it reached the large intestine and
decomposed in it the starch of farinaceous food into sugar, of which
the acid products prevented the swarming of putrefying microbes. By
this process it is possible to reduce to a minimum and even sometimes
to eliminate the production of phenol and indol in rats subjected to a
mixed diet and made at the same time to ingest cultures of the lactic
bacillus and of the glycobacter.

Metchnikoff applied these different diets to himself and to other
individuals and obtained concordant results.

However, he ascertained that it is not only the food diet which
regulates the quantity of microbian poisons contained in the organism;
that quantity sometimes varies very much in spite of an identical
diet. He thought that a very important part of influence is due to
pre-existing microbes which prevent or favour the development of
microbes of putrefaction. All these questions, complicated by the
richness and variety of the intestinal flora, still demanded a long
series of laborious researches.

At the end of the winter he felt tired, and we went to the seaside
during the holidays. But the sharp sea air did not suit him; he had
a beginning of cardiac asthma and nearly fainted during a walk. We
therefore had to come away from the sea, and went inland, to Eu. At the
beginning of our stay, Metchnikoff did not feel well, walking tired
him, he suffered from cardiac intermittence; it was only gradually
that his condition improved and he was able to write the preface to a
Russian edition of his philosophical articles.

This book was entitled _Forty Years' Search for a Rational Conception
of Life_, and the articles record the evolution of his ideas and his
search "not only for a rational understanding of life, but also for the
solution of the problem of death, which is so full of contradictions."

This collection of articles enables us at the same time to follow the
gradual transition from the pessimism of his youth to the optimism of
his maturity. His first writings[28] relate to the discords of human
nature and the lack of a solid basis for morals.

  [28] _Education from an Anthropological Point of View_, _The
       Matrimonial Age_, _The Conception of Human Nature_, _The
       Struggle for Existence in a General Sense_. See Bibliography.

But, already in 1883, he concluded an opening _Causerie_ at the
Naturalists' Congress in Odessa, by the following words: "The
theoretical study of natural history problems, in the widest sense of
the word, alone can give a sound method for the comprehension of truth
and lead to a definite conception of life--or at least to an approach
to it."

Another article, _The Curative Forces of the Organism_, sums up his
phagocyte theory, and states the fact that the organism possesses
special powers of struggle against enemy elements.

In 1891, he wrote _The Law of Life_, in which we find the dawning idea
that the lack of harmony in human structure does not make a happy
existence and a rational code of morals impossible. Morals must consist
"not in rules of conduct adapted to our present defective human nature,
but on conduct based upon human nature modified, according to the ideal
of human happiness."

_The Flora of the Human Body_, published in 1901, is a study in which
Metchnikoff's optimism assumes a definite form, for he speaks of the
efficacy of certain means of struggling with our lack of harmony.

The last chapter in the book, "A Conception of Life and of Medical
Science," introducing the word Orthobiosis, strikes the optimistic
chord, winged and conclusive, which must result from victory over the
disharmonies of human nature. This is Metchnikoff's ultimate formula,
summing up the problems of life and of morals:

  The ethical problem reduces itself to this: to allow the majority of
  human beings to reach life's goal, that is, to accomplish the whole
  cycle of a rational existence to its natural end. We are still very
  far from that. We can but sketch the rules to follow in order to
  attain this ideal. Its final realisation will demand more scientific
  researches, which must be allowed the widest and freest scope. It is
  to be foreseen that existence will have to be modified in many ways.
  Orthobiosis demands an active, healthy, and sober life, devoid of
  luxury and excess.

  We must therefore modify present customs and eliminate those extremes
  of wealth and poverty which now bring us so many evils. As time goes
  on, when Science has caused present evils to disappear, when men no
  longer tremble for the life and welfare of their dear ones, when
  individual life follows a normal course--then Man can attain a higher
  level and more easily devote himself to exalted goals.

  Then Art and pure Science will occupy the place which is due to them
  and which they lack at the present moment in consequence of our many
  cares. Let us hope that men will understand their true interests and
  contribute to the progress of orthobiosis.

  Many efforts are necessary, much self-sacrifice, but they will be
  attenuated by the consciousness of an activity directed towards the
  real goal of human existence.




CHAPTER XXXIII

                            First our pleasures die, and then
                            Our hopes, and then--our fears, and when
                            These are dead--the debt is due.
                            Dust claims dust--and we die too.

                                                            SHELLEY.

  Unpleasant incidents--The fabrication of lacto-bacilli--St.
  Léger-en-Yvelines--Return to Paris--First cardiac attack--Evolution
  of the death-instinct--Notes on his symptoms.


The end of 1912 had some unexpected emotions in store for us.

Metchnikoff had always been able to congratulate himself on the cordial
hospitality which he had found in France, and to the end of his life he
remained deeply grateful for it.

But, in any country, incidents may occur about which it would be
unjust to generalise when they are due to individuals or to particular
limited circles, as was the fact in the present case. In spite of the
broad and generous ideas so widespread in France, a sudden current
of narrow nationalism became manifest, at this moment, in certain
quarters. Foreigners were accused of invading the country, of occupying
lucrative posts and increasing the difficulties of the bitter struggle
for existence. At first, only vague allusions were made, but, little
by little, the attacks of that nationalist circle went beyond all
bounds of justice and decency and turned into brutal provocations. The
contemptuous word _métèque_ was resuscitated.

One newspaper especially led a furious propaganda and hesitated at no
means of overwhelming its victims, one of whom was Metchnikoff.

Those coarse attacks might have been ignored with the contempt which
they deserved had they not been echoed by a writer in a serious
publication. Dr. Roux then wrote a reply in the same paper, and the
campaign ceased.

A proverb says with truth, "Slander away! something will always
stick." And it was thus in this case. Metchnikoff was reproached with
having made money by his scientific discoveries. The story of his
whole life and the fact that he left no fortune should suffice to
answer this calumny, yet I am obliged to dwell on it, though I should
have preferred not to do so. The incident is too characteristic of
Metchnikoff to be omitted in this biography, which must be a faithful
testimony. The calumny was based on a real fact, but the interpretation
of it was absolutely false. After Metchnikoff's experiments on the
lactic bacillus, a notion of the hygienic power of pure sour milk began
to spread among the public. A manufacturer had the idea of preparing
it on a large scale, according to the new scientific principles, and
wished to form a company to that effect; he asked Metchnikoff to
recommend to him some one whom he could entrust with the technical work
of preparing the pure curded milk. It happened that we were just then
trying to find a post for a young couple in whom we were interested,
and whose child was my husband's goddaughter. He trained his protégé
in the technique required, and was therefore able to recommend him.
A short time later, the manufacturer declared that he could not be
sure of the success of his enterprise without the guarantee of the
name of Metchnikoff, whose researches had proved the advantages of
the preparation in question. After consulting the legal adviser of
the Pasteur Institute, Metchnikoff consented to this, without of
course having any pecuniary interest in it; the formula chosen was,
"sole provider of Professor Metchnikoff." The undertaking succeeded,
and our protégé's future was assured. Metchnikoff himself, however,
was attacked and accused most unjustly, though he had never made any
personal profit whatever from the enterprise. And yet, when his friends
told him that it had been very reckless on his part thus to expose
himself, he answered that he thought it impossible to hesitate between
the welfare of a whole family and the possibility of gossip. His
reasoning was imprudent and perhaps erroneous, but he never hesitated
between doing a kindness and the possible unpleasant consequences it
might have for himself. If some people could not understand him, it was
because he was far from the commonplace, "not like other people," a
quality often misunderstood and unforgiven.

Such are the facts. "Honi soit qui mal y pense!"

The desire to lessen the ills around him was, in general, the cause of
heavy anxieties in his later years. He had learnt that the discovery of
an industrial process, of which the realisation required capital, would
be an excellent investment. He immediately wished to make his friends
profit by it, as well as himself, in order to alleviate material
difficulties. But until the end of his life the undertaking had no
results, and he was obsessed by the fear of having given bad advice to
those who followed him.

He knew not how to refuse, even when he should have done so; therefore
he was odiously exploited. Often he worked, in his rare leisure
moments, for people who were unworthy of his kindness. During the last
years of his life, all these incidents grieved him so much that he used
to say he felt the burden of existence. His soul was darkened, he felt
very depressed, and his health suffered.

We spent the summer holidays of 1913 at St. Léger-en-Yvelines, a
pretty place on the edge of the Rambouillet forest. In his choice of a
holiday resort, my husband was always guided by the desire to find a
place favourable to my sketching, and St. Léger answered the purpose
wonderfully. The fields with their vast horizons, the forest with its
graceful bracken and carpets of softly-tinted heather, the mysterious
ponds, all went to compose an admirable symphony, full of artistic
suggestion.

Elie himself was gay and full of spirits. He worked in the morning, and
we spent the rest of the day in the forest. He often read aloud; he
rested and enjoyed the peaceful calm, pure air, and verdure which he
loved so much.

He had arranged to take advantage of these holidays to execute work of
which he had been thinking for a long time. As it has been said above,
he thought that the life instinct was only developed gradually and
produced at the same time an optimistic conception of life; he wished
to verify this personal impression by the psychological evolution of
divers other thinkers. He turned to Maeterlinck, as a representative of
modern ideas. This author, mystical and pessimistic in his youth, had
acquired in his maturity a far more optimistic conception of life. He
himself explained this change by the influence of circumstances, but
Metchnikoff saw in it a deeper cause, connected with the progressive
evolution of the vital instinct which, by bringing equilibrium with
it, suggests optimism. The study of Maeterlinck's works confirmed his
opinion.

Time flowed peacefully between rest and these occupations; at the end
of the holidays, we congratulated ourselves on their result on my
husband's health; on our return, his friends thought him looking well.
Yet on the 19th October, about seven in the morning, he had a terrible
cardiac attack without any apparent cause. I found him seated at his
desk, and was terrified by his appearance; his lips were blue, and he
was breathing with difficulty. And yet he was writing, and this is what
he was writing:

                           SÈVRES, _19th October 1913_, 7.45 A.M.

  This morning, after a good night, my heart was working well; I had
  from 58 to 59 regular pulsations. But, as I rose, I suddenly felt
  acute pain along the sternum; at the same time began a strong crisis
  of tachycardia. I had never in my life felt anything like it....

Here he had to stop as the crisis was becoming intolerable, but a few
hours later he took up his pen again:

                                           _19th October_, 3 P.M.

  The crisis lasted till one o'clock (six hours' duration).

  There were times when the pain in the chest was unendurable.

  I was thirsty and drank hot, weak tea; I vomited; I felt wind in the
  stomach and the intestine. About noon the pain decreased, but the
  heart-beats were frequent and extremely irregular. I lunched in
  order not to alarm my wife, though I feared to aggravate the attack
  by filling my stomach.

  But the opposite happened. From the first mouthfuls (I naturally
  eat very little) the pain became more tolerable and the pulse less
  frequent. After lunch, everything became normal again; the pain
  ceased, the pulsations slackened (78-80 per min.) and became much
  more regular. Intermittence was rare, and I several times counted
  100 regular beats in succession. I remained absolutely conscious
  during the whole crisis, and what chiefly pleased me is that I felt
  no fear of death, which I was expecting at every moment. It was not
  only _reasoning_ which made me understand that it was better to die
  now, whilst my intellectual powers had not yet gone from me and I had
  evidently accomplished all of what I was capable; I resigned myself
  also _in feeling_, and quite serenely to the catastrophe which was
  coming upon me and which would be far from unexpected.

  My mother, who had suffered from heart attacks during a great part of
  her life, died at 65. My father died of apoplexy in his 68th year.

  My eldest sister succumbed to an oedema of the brain; my brother
  Nicholas died at 57 of _angina pectoris_.

  Undoubtedly my cardiac heredity is a bad one. Already in my youth, I
  suffered from my heart. At 33 I had such cardiac pains that sometimes
  I had to rest after walking a few paces. At 34, I had much giddiness
  and a feeling of heaviness in the head. I could not read a few lines,
  a poster even, without a painful sensation. In 1881, during relapsing
  fever, I had severe cardiac intermittence, very fatiguing and only
  relieved by small doses of digitalin.

  I afterwards had periodical attacks of intermittence but never any
  tachycardia, at least none that lasted more than a few seconds.
  A little tincture of strophanthus used to relieve me during
  intermittence. I ended by consulting Dr. Vaquez, but the treatment
  he prescribed gave me no relief. As I attributed my condition to
  poisoning by the toxins of intestinal microbes, I resolved to give
  up raw food and to purge myself now and then with Carabaña water.
  The success of this treatment was indisputable, and in 1897 the
  intermittence ceased. In the autumn of 1898 I was beginning to suffer
  from polyuria; I consulted Albaran, who counselled Contrexéville
  water, but this cure caused the appearance of _albumen_ in my urine.
  In 1898 I consulted Norden at Frankfort and Leube in Paris during
  the Exhibition of 1900. Neither found anything alarming. Norden had
  told me that I had _symptoms of arterio-sclerosis inherent to my age_
  (53). I adopted a mixed diet; I took, regularly, sour milk prepared
  with cultures of the Bulgarian lactic bacillus, and, during some
  years, my health was quite satisfactory.

  It was only after my journey to Russia in 1909 that a notable
  aggravation supervened. I felt acute pains in the chest, along the
  sternum, especially after eating or walking.

  In 1911 the intermittence reappeared. In January 1911, I consulted
  Dr. Heitz in order to know whether I could undertake an expedition in
  the Kalmuk steppes, where hygienic conditions are very unfavourable.
  Dr. Heitz found my heart hypertrophied, some slight galloping noise,
  the blood-pressure (Pachon's apparatus) 17-16-15. He said, however,
  that I might undertake the journey, but added, "People die suddenly
  with less the matter than that with their hearts." The journey went
  well, though I suffered from frequent intermittence and pains along
  the sternum when I walked.

  After my return, my heart was fairly satisfactory.

  What consoles me especially is that I have preserved my activity, my
  passion for work, and my intellectual powers. But, naturally, I am
  ready to die at any moment.

  At the beginning of the summer I was sounded by Dr. Manoukhine and
  Professor Tchistovitch; both thought the heart-sounds satisfactory,
  but Manoukhine was rather struck by the weakness of the first
  aortic sound whilst the second was very strong. I had frequent
  intermittence, but with intervals of normal pulsations. Latterly I
  have felt better in that respect, and the pain along the sternum only
  occurred in exceptional cases.

  Whilst preparing for my end, I am glad that I can face it with
  courage and serenity.

  As I look back upon my life, it seems to me to have been as
  "orthobiotic" as possible.

  If it may seem premature to die at 68 years and 5 months, it must not
  be forgotten that I began to live very early (I published my first
  scientific work at 18); that I have had many emotions during my life;
  that I was, so to speak, in a state of continual ebullition.

  The polemics concerning phagocytosis might have killed or finally
  enfeebled me much earlier. At times (for instance, I refer to
  Lubarsch's attacks in 1889 and those of Pfeiffer in 1894) I was ready
  to rid myself of life.

  Moreover, I only began to follow a rational hygiene (according
  to my opinion) after I was 53 years old and already had symptoms
  of arterio-sclerosis. I have been fairly successful in combating
  intestinal putrefaction (phenols and indols),[29] but I could not
  succeed in getting rid of abundant _clostridium butyricum_ which were
  implanted in my intestine.

  To sum up, I rejoice that I have had an existence not devoid of
  sense, and I feel some satisfaction in considering my conception of
  the problem of life as being accurate.

  As I prepare to die, I have not the shadow of a hope of a life
  beyond, and I calmly look forward to complete annihilation.

  It is possible that having very early begun a very intense life, I
  have attained at 68 a precocious satiety of living, just as certain
  women cease to menstruate earlier than the great majority.

                                                 EL. METCHNIKOFF.

  _P.S._--I believe everything is in order in view of my end (my will,
  my affairs, etc.).

  _P.S._--Let those who think that, according to my principles, I
  should have lived a hundred years, "forgive" me my premature end in
  view of the extenuating circumstances above-mentioned (intense and
  precocious activity, excitable temperament, nervous disposition, and
  late beginning of the rational diet).

                                                            E. M.

  [29] 28th _June_ 1914.--I have again analysed my urine and I
       again find indican in fairly large quantities in spite of
       a diet which is as rational as possible. I am trying to
       elucidate this strange contradiction.

The very next day he felt well enough to return to his work.

When urged to settle down in Paris in order to avoid the fatigue of
the journey, he replied that the peace and pure air of Sèvres were
indispensable to his health, that the journey did not fatigue him in
the least, but on the contrary provided him with wholesome exercise and
a pleasant walk. Knowing how prudent he was, I did not dare to insist
for fear of mistaking what was really best for him. And life gradually
resumed its normal course....

For a long time Metchnikoff had been observing himself very
attentively; he took regular notes on the influence of the food
diet which he followed; by the analysis of his urine, he sought for
indications respecting the toxic products of his intestinal flora; he
studied upon himself the advance of senility, whitening of hair, etc.

Since his crisis he had adopted the habit of writing occasional notes
on his psychical state. This is what he wrote on the 23rd December 1913
at Sèvres:

  Two months and more have passed since I wrote the preceding lines.
  During that period my health has been satisfactory; nevertheless I
  have wondered every day whether it would be my last.

  I am therefore hastening to write my memoir on infantile cholera.

  The cardiac intermittence has been more or less frequent, yet every
  day I have had periods of regular pulsations (58-66-72 per minute) as
  usual.

  The day before yesterday I contracted a bad cold, accompanied by a
  little fever. Wondering if it would degenerate into pneumonia, I
  faced anew the possibility of a near end, and I resumed the analysis
  of my thoughts, feelings, and sensations.

  As my 70 years draw near to their close, it seems to me that a
  feeling of satiety with life, what I call the "natural death
  instinct," is gently beginning to evolve.

  When, in autumn 1910, experimenting with typhoid cultures, I had
  soiled my face and mouth, I naturally said to myself that it might
  give me typhoid fever. I washed my face and beard with soap and a
  solution of sublimate without considering that I was safe against
  the infection. I _reasoned_ that it would be preferable to contract
  the disease and to die of it. (At my age typhoid fever is almost
  always fatal. I had never had it, and might therefore consider myself
  in a state of receptivity.) It is fine to fall on the battlefield,
  especially at an age when life and activity are already on the
  wane. But all that was pure _reasoning_; _instinctively_ I still
  felt a great desire to live, and it was with joy that I counted
  the days which separated me from the danger of having contracted
  typhoid fever. I felt much relieved a fortnight after the incident,
  considering that the limit of incubation was passed.

  Thus _reasoning_ and feeling or _instinct_ were not in accord.

  Since then, in the three following years, a modification has taken
  place in my psychical condition.

  The prospect of death _frightens me less than before_. During my
  cardiac crisis of the 19th October 1913 I even felt no fear of death,
  and my satisfaction at my recovery was _less_ than before.

  I think it is that difference in quantity which constitutes the first
  symptoms of _indifference_ towards death, an indifference which is
  hardly perceptible at first.

  Satiety with life is sometimes observed in old people of 80; it is
  not surprising to feel the first approach of it about 70, especially
  in the case of a man like myself who began very early to lead a very
  intense life.

  Other special circumstances influence even more this precocious
  satiety of life. As I become more indifferent to my own life I feel
  a more and more acute anxiety for the health, life, and happiness of
  those who are dear to me.

  I am especially troubled by a consciousness of the imperfection
  of modern medicine. In spite of the progress realised in these
  latter days, it is still powerless against a multitude of diseases,
  threatening us on all sides.

  Pulmonary lesions (tuberculosis, pneumonia, etc.), the nephrites, and
  an infinite quantity of other diseases can yet neither be prevented
  nor cured. So we live in constant fear for those we love. When
  medicine shall (as I am persuaded) have conquered all these evils,
  one cause of the bitterness of life will cease--but that is not yet
  the case.

  That is why, besides the weakening of the life-instinct, a
  resignation towards death grows in us, as a means of no longer
  feeling the ills which afflict our neighbours.

  With time, when that source of unhappiness has been eliminated by
  medicine, old age will be more attractive, and an orthobiotic life
  will become normal and realisable.

  At the ages of 50, 60, 65, I felt an intense joy in living, such as I
  described in my _Studies on Human Nature_ and _Optimistic Essays_. In
  the last few years it has lessened markedly.

  Scientific work still provokes in me an invincible enthusiasm, but I
  am becoming more indifferent to many of the pleasures of life.

And indeed he no longer had the joyous soul of former days; into his
life a funereal note had crept, low but continuous and obstinate. He
gave all the more energy to the study of those questions the solution
of which was to bring about the reign of orthobiosis. He spent
the whole winter in researches on the intestinal flora and on the
completion of his studies on infantile cholera.

In the spring, on the occasion of his anniversary, he wrote the
following:

                                         SÈVRES, _16th May 1914_.

  I have to-day entered my 70th year; it is a great event for me. As I
  analyse my feelings, I realise more and more the _weakening_ of my
  "life-instinct."

  In order to verify my impressions, I wished to hear again the
  musical compositions which formerly used to make me shed tears of
  enthusiasm (for instance, Beethoven's 7th Symphony or Bach's aria
  for the violin). Well, my impressionability towards music has very
  much lessened. In spite of the facility with which old people weep, I
  hardly shed a single tear, save with rare exceptions.

  I observe the same change in other circumstances.

  This spring, the blossoming of flowers, buds, bushes, and trees, all
  this renascence of nature, has not excited in me a shadow of the
  emotion of preceding years.

  Rather I felt a melancholy, not on account of my coming end, but
  because of the consciousness of the burden of existence.

  There is no question for me now of the old joy of living; my
  predominant feeling is _infinite anxiety_ for the health and
  happiness of those I love. I now so well understand Pettenkoffer,
  who committed suicide at 84 after losing all his family. Their
  death had evidently been precocious because of the impotence of
  medicine. At every step, one comes across cases where neither
  hygiene nor therapeutics can do anything. How many are infected with
  tuberculosis, no one knows how or where. What is to be done to avoid
  it? And the consequences of measles, of scarlet fever, perhaps of a
  simple sore throat, followed sometimes by tuberculosis or nephritis!

  What is the use of being able to foretell, by means of the proportion
  of urea in the blood, the precise moment of the death of an
  "azotemic" patient when you cannot prevent it or cure him?

  This imperfection of medical science prevents many from reaching true
  _orthobiosis_, and it is understandable that, seeing the present
  state of medicine, the feeling of the "burden of existence" may be
  precocious, as in my case.

  But it is indubitable that, in spite of the slowness with which
  medical science is developing, it will in the future reach a degree
  which will enable us to cease to tremble any longer before all sorts
  of incurable diseases. Orthobiosis will then appear, no longer under
  its present incomplete form, but as the solid and essential basis of
  life.




                             CHAPTER XXXIV

  Return to St. Léger-en-Yvelines--Norka--Studies on the death of the
  silk-worm moth--War declared--Mobilisation.


The drawback of the holidays consisted, for Metchnikoff, in coming away
from his laboratory and in the impossibility of following his diet in a
hotel or a boarding-house. We therefore resolved to hire a cottage in
some quiet place, to organise a small laboratory, and to continue our
usual mode of life.

St. Legér-en-Yvelines, where we had spent part of the preceding summer,
answered all our requirements. We took a small villa there and called
it "Norka," which means in Russian "little hole," "little refuge," and
came there for the holidays in July 1914.

Elie seemed pleased to be there; thanks to the laboratory, he could
easily vary his occupations, for continuous reading fatigued him. His
reflections having led him to the problem of natural death, he had
for some time been seeking for a subject on which he could study the
mechanism of the phenomenon. He had formerly studied the May-flies
(Ephemeridæ), predestined to a natural death by their rudimentary
buccal organs, incapable of use in feeding. But the life of those
insects, a life of a few hours or a few days at the most, was too short
to allow the necessary researches. The males of the Rotifera, which are
also deprived of buccal organs and even of digestive organs, were too
small in size for physiological experiments. Thus, those two examples
of natural death among multicellular beings were unsuitable to the
projected study.

He found a more favourable subject in the moth of the silk-worm
(_Bombyx mori_); the rudimentary buccal organs of that insect make all
feeding impossible and predestine it to a natural death. The dimensions
of the silk-worm moth are large enough and it has a life duration of
twenty-five or thirty days, therefore sufficient to allow the study of
the mechanism by which its death is brought about. Metchnikoff procured
a quantity of silk-worms, and soon the moths hatched and covered all
the mantelpieces and tables in Norka with white flakes. He ascertained
that it was not hunger which brought about the death of the moths, for
their organism was not in the least exhausted.

The nutrition of the latter takes place at the expense of the fatty
substance which remains after the metamorphosis of the chrysalis into
a moth. The dissolution of this fatty substance produces toxins which
pass into the urine. Thus the obvious cause of the death of the moth
is an acid intoxication by toxic urine secreted in the bladder. As the
latter does not empty itself, uræmia becomes inevitable.

The majority of moths contain no micro-organisms which could suggest
death by infection.

The only theoretic objection against a natural death might consist
in the existence of "invisible microbes." Indeed, the question
of invisible microbes revealed in certain infections perturbed
Metchnikoff's mind to such an extent that, during his last illness,
he used to say that it would have been a curse to his ulterior
activity, a sort of ghost preventing all definite conclusions in
problems connected with the absence or presence of microbes. The last
word on natural death, he said, will only be spoken when, owing to
the improvement of the microscope, those microbes which are as yet
invisible to us will become visible. Nevertheless, as far as can be
judged at present, the death of the _Bombyx mori_ is due, not to
external causes, but to the structure of the insect itself, and is
therefore a natural death.

During these holidays, Metchnikoff also wrote reminiscences of his
friend the physiologist Setchénoff.[30]

  [30] In the Russian Review, _Messenger of Europe_.

We went quietly for fairly long walks; Metchnikoff rested on the shores
of his favourite lake (Vilpert), and his health was very satisfactory.

After the intense heat, some rain came and the weather became ideal;
there was a perceptible lull in nature; the underwood was becoming
purple with heather; the corn was ripening; harvest had begun, and
sheaves stood up in the fields. All was calm and peaceful; we never
tired of the charm of the forest, of the fields, of the beautiful
rustic surroundings, and our souls sang in unison with Nature....

Suddenly, like a flash of lightning in the pure sky, the news of the
war burst out!

The possibility had so often been mentioned in late years that no one
believed in it. Even now, on the eve of the catastrophe, it was hoped
that all would settle down....

Until the last moment Metchnikoff refused to believe in it; he could
not admit that a pacific solution was impossible. "How is it possible
that in Europe, in a civilised country, mutual interests should not be
reconciled without killing?" he said. "A war would be madness, even
from the point of view of Germany, who risks having to face three great
powers. No, war is not possible."

And yet war was spreading all over Europe.

The situation of France seemed critical, for the country had just gone
through a series of internal storms. The labour question, that of
income tax, and that of the three years' military service had raised
sharp controversies; the Caillaux affair had revealed hidden sores in
political life; the insane assassination of Jaurès, of which the reason
was still unknown, gave rise to the blackest prognostications.

Already on the 28th July, date of the declaration of war by Austria
against Serbia, anxiety had become intense, but it was hoped that
Russia would settle matters between the two countries, and that the
trouble would remain local.

On the 1st August, Germany declared war on Russia, and it became
obvious that the storm was coming on apace. The aspect of life suddenly
changed; a feeling of dread and expectancy unnerved everybody;
mobilisation was mentioned; automobiles at full speed hurried along the
roads; the harvest was hastily gathered.... We could no longer work, go
for walks, or admire nature without a feeling of heavy anxiety.

We went about like automatons, all our thoughts centred on one
point--the threatening, inevitable war. Everything had put on a
sinister aspect, and Nature herself joined in the general gloom; the
weather became stormy, thunder rolled alarmingly, heavy clouds hurried
and met in a gigantic struggle, evoking the image of other coming
struggles. During the night of the 1st August the storm never ceased,
we could not sleep; all night long, frenzied automobiles raced along
the high road, sounding their lugubrious horns. In the middle of the
night, we heard some one knocking at the doors of the police station
opposite. What was happening? In the darkness, illumined by flashes of
lightning, we saw horsemen with lanterns; they were messengers bringing
the orders for mobilisation. It was proclaimed the next day.

The population gathered at the _mairie_, a grave, silent crowd; the few
words exchanged only concerned war and partings. Old men, who had lived
through 1870, were low-spirited; young ones, on the contrary, were
excited.

We had to think of our return home, which might be difficult later.
We went into the forest for the last time; the evening was mild and
calm after the storm. The peace and beauty around us were such that
we longed not to believe in the terrible reality. But we had to bid
farewell to all that had charmed us. We went once again into the
meadows near Norka. The hayricks were standing in rows, their soft,
golden silhouettes harmoniously outlined against the hilly background
purple with heather. We sat down on the mown grass. Suddenly, in the
calm of the evening, bells began to sound. It was not the distant and
poetic call for vespers, nor the sad sound of the passing bell, but the
hard, sinister, ill-omened tocsin, warning the whole countryside, down
to the most distant, most peaceful hamlets and to the wood-cutters in
the forest, that mobilisation had commenced....

Another storm broke out in the night. Again the rolling of the
thunder shook our nerves and seemed like the echo of distant battles;
again mysterious automobiles and horsemen raced along the road, and
everything, every sound, every shadow seemed sinister.

We did not feel any fear, but a kind of insupportable nervous tension.
Later, when we were much nearer real danger, we did not experience this
electric, almost morbid feeling.

The next day, Germany had declared war on France.

It was only with much difficulty that we found a carriage to take us
to the station. On the road we were constantly being passed by various
vehicles, crowded with soldiers and young men going off. The little
station was full of people, the train also. Moved and excited, the
people shouted, "Vive la France!" and sent friendly salutes to unknown
soldiers in the train. Women, seeing their men off, were trying to be
gay; they encouraged the departing ones, and only wept after they were
gone. The general impression, both moral and material, was excellent;
every one seemed equal to his task, conscious of his duty, and desirous
of fulfilling it well. The mobilisation seemed well organised,
everything was being accomplished without any flurry or bustle, even
the trains were almost punctual.

All small personal interests and party quarrels which had latterly
poisoned life now suddenly disappeared; everywhere the desire to be
useful was noticeable; people became better, there was more sympathy,
more solidarity; the distance between classes seemed to decrease, the
common trial made all equal.

There was beauty in that moment, for it showed that the greatest of
evils might yet exalt and purify the human soul.




                             CHAPTER XXXV

  Return to Paris--The deserted Institute--Memoir on the Founders of
  Modern Medicine--Metchnikoff's Jubilee--Last holidays at Norka.


This was but the beginning of the war; soon it spread with vertiginous
rapidity, and made its cruel destructive force felt.

On our return from Norka, we found everything on a war footing. The
very next morning, Metchnikoff hurried to the laboratory. He only
reached Paris with some difficulty, all means of communication being
encumbered by soldiers. He had left the house nervous and excited but
full of courage and energy. I shall never forget his return home....

I was awaiting him as usual, just outside the station, and, as he got
out of the train, I did not recognise him. I saw a stooping old man,
bent as under a heavy burden; his usual vivacity was gone, and had
given place to the deepest depression.

He told me in a broken voice that the Institute was already deserted;
that it was under the orders of the military authorities, and
completely disorganised for scientific work. The younger men were
mobilised; the laboratories empty; the animals used for experiments had
been killed on account of the departure of the servants, and for fear
of a lack of food. Everything that had been devoted to the service of
science and of research into means of preserving life had been handed
over to the service of war. Normal and cultured life was arrested. And
that was the outcome of civilisation.

Metchnikoff felt as if he had suddenly been dropped into the abyss of
centuries, into the times of human savagery. He could not accustom
his mind to the idea of such a fall; it seemed to him a paradox, an
impossibility, that civilised peoples could not do without sanguinary
fights in order to solve questions of mutual relations.

The events which were taking place agitated and depressed him all the
more that he had not the possibility of becoming absorbed in scientific
investigations; he was completely thrown off his balance.

And as, one by one, the news came of the death in action of several
of the young men who had left the Institute, Metchnikoff's grief knew
no limits. He could not bear the idea, now a terrible reality, that
these brilliant young lives should be sacrificed, victims of those who
should have directed the peoples towards peace and a rational life,
and who, instead of that, threw the most precious part of humanity
into the abyss of death. War became a dark, sinister background to
his daily life. The victims of war were not only those who fell on
the battle-field, but included him whose whole life-effort had been
directed towards the conservation of human existence and the search
for rational conceptions. The contrast between his aspirations and the
cruel reality had been to him a blow which his sensitive and suffering
heart was not fit to bear.

The Germans were advancing rapidly. Then came the sad days of panic,
when the inhabitants were leaving Paris in numbers and the Government
started for Bordeaux. At night, the sky was swept by the gigantic,
luminous sword of the searchlights; the rumble of cannon could be heard
in the distance....

Metchnikoff, however, had no personal fear whatever. He very simply
decided on his course of action, which was to remain at the Institute
if his presence there could be of use; if not, to retire to some quiet
place where he could work. As there was hardly any staff left at the
Institute on account of the mobilisation, he did not go away, but, on
the contrary, we came to live in Paris, the communication with Sèvres
being very difficult.

The day we arrived was that on which the first German aeroplanes
appeared, and they dropped bombs near the St. Lazare station just as we
were alighting from the train. For some time after that, they carried
out a raid above Paris every Sunday.

In spite of the disorganisation of his whole life, Metchnikoff had
succeeded in resuming his work to a certain extent. He took advantage
of an opportunity to observe an old dog who was suffering from
diabetes, and hastened to examine his organs as soon as he died, whilst
they were still fresh. He had for some time supposed that diabetes
might be an infectious disease; yet he was unable to discover any
specific microbe either in the humors or in the organs of the dog. But
he succeeded in provoking symptoms of the disease (traces of sugar in
the urine) in a healthy dog, by inoculating him with the pancreatic
gland of the diabetic dog. He was much encouraged by this result,
and would have liked to continue his researches, but was unable to
do so because of the general disorganisation and the impossibility
of obtaining animals for experiments. He had to content himself with
continuing his memoir on infantile cholera and his observations on the
silk-worm moth.

As he was almost altogether precluded from laboratory work, he began
to write a study on "The Founders of Modern Medicine," in order to
demonstrate, by concrete examples, the importance of positive science
in its application to life. This is what he said in his preface to the
book:

  These pages were written under special circumstances. If not in the
  actual hearing of guns, it was in expectation of it that I had to
  spend several weeks in my Paris laboratory, now under war conditions.
  These meant an almost complete cessation of any scientific activity
  in our Institute.

  For fear of a lack of food, the animals used for our experiments had
  been killed, which deprived us of the possibility of proceeding with
  our researches.

  The stables of the Institute were filled with cows who provided milk
  for the hospitals and children's homes.

  The greater number of our young collaborators, assistants, or
  laboratory attendants were mobilised, and only the female employees
  and old men remained. One of the latter, I found myself in the
  impossibility of pursuing my investigations and in possession of much
  leisure. I made use of it to write this book in the hope that it
  might be helpful.

  It is not intended for physicians, for they know all that is
  expounded in it, but for young men who are seeking a scope for their
  activities.

  We may be sure that the insane war which broke out in consequence of
  the lack of knowledge or of power of those who should have watched
  over peace, will be followed by a long period of calm. It is to be
  hoped that this unexampled butchery will, for a long time, do away
  with the desire for fighting, and that soon the need will be felt
  of a more rational activity. Let those who will have preserved the
  combative instinct direct it towards a struggle, not against human
  beings, but against the innumerable microbes, visible or invisible,
  which threaten us on all sides and prevent us from accomplishing the
  normal and complete cycle of our existence.

  The results acquired by the progress of the new medical science allow
  us to hope that, in a more or less distant future, humanity will be
  freed from the principal diseases which oppress it.

After describing the state of medical science before Pasteur, Lister,
and Koch, Metchnikoff compared with it modern medicine, created by
these three Founders, and showed the great horizons opened by them to
the medicine of the future.

On the 26th of September 1914, whilst we were still in Paris, he had,
in the laboratory, an attack of tachycardia, which lasted three hours
but was much less violent than that of the year before. The winter,
however, passed fairly well in spite of the emotions and continuous
excitement caused by the war, and he had no other attack until April
1915, when again he had a slight tachycardiac crisis of a short
duration. Yet he was very much changed: his hair was much whiter, his
movements were slow, and his figure bent. His infectious gaiety and
vivacity had disappeared, but he remained energetic and enthusiastic in
his work, and gained more and more in serenity.

Little children in the street called him "Father Christmas," and came
confidingly to ask him for presents. They knew him well, and were aware
that his pockets were always filled with sweets for them. He used
to say that his growing love for children was the revelation of the
grandfatherly instinct, for which he had reached the proper age. He
especially loved one of his god-daughters, little Lili; he had become
attached to the child on account of her kind heart and exceptional
sweetness, and also because, from the cradle, she had shown a marked
preference for him. And yet his love for children was not to him a
source of joy, for anxiety on their account predominated over other
feelings.

In spite of the physical change which had supervened, his brain
continued to work untiringly as in the past, and he tackled new
problems with youthful courage and boldness. He had planned a work on
the sexual question, which, according to him, was treated erroneously,
with the result that grave disharmonies occurred in human existence.

Thus he reached some quite revolutionary conclusions respecting
education and marriage. He thought that morality should be set upon
a quite different basis, new and rational; and that was the question
which he prepared to treat.

The 16th of May of that year was his seventieth anniversary.

His satisfaction was great at having reached the normal limit of age,
for he saw in that a conclusive proof of the efficacy of his hygiene.
Indeed, he showed on that day a sort of rejuvenation: his aspect was
quite different, he was gay and animated as he had not been for a long
time.

The Pasteur Institute celebrated his jubilee. In spite of the absence
from "The House" of many members on account of the war, the library
filled with people, and the fête had a cordial and intimate character.
Dr. Roux's speech[31] will remain the best description of E. Metchnikoff
and of his scientific activity. He himself responded to all those
manifestations of sympathy by a spirited speech, in which, _à propos_
of his own particular case, he expounded his ideas on senility and the
duration of life in general. This is what he wrote on that same day in
his note-book:

  [31] _Annales de l'Institut Pasteur_, Jubilé d' E. Metchnikoff,
       1915.

  16th May 1915. To-day I have at last accomplished my seventy years!
  I have attained the normal limit of life, a limit mentioned by King
  David and confirmed by the statistical researches of Lexis and
  Bodio.[32] I am still capable of work and of reflection. But the
  changes in my psychical state which I had observed a year ago have
  become sensibly accentuated. The difference in acuteness both of
  pleasant and painful sensations is becoming more and more marked.
  Agreeable sensations are becoming weaker; I am now indifferent to
  many things which I used to appreciate very much.

  It is useless to say that I am indifferent to the quality of my food;
  my need of musical impressions has become so much less that I hardly
  feel the desire to satisfy it. The charm of spring no longer touches
  me and only provokes sadness in my mind.

  On the other hand, my anxiety for the health and happiness of those
  I love is getting more and more acute. I find it difficult to
  understand how I ever could bear it.

  The powerlessness of medicine grieves me more and more, and,
  as a last straw, the war has interrupted all the work that had
  been undertaken against disease. In these conditions, it is not
  astonishing that I should feel a growing satiety with existence.
  Last year [16th May 1914 to 16th May 1915] I had two attacks of
  tachycardia, during which I should have been glad to die, but in
  general my health is satisfactory and that sustains me. What would
  have become of me if, to crown my misfortunes, I had fallen ill! I
  certainly no longer fear death, but I desire to die suddenly during a
  heart attack and not to go through a long illness.

  My comparative longevity is not due to family heredity (my father
  died in his 68th year, my mother in her 66th, my sister also, my
  eldest brother at 45, my second brother at 50, the third in his 57th
  year; my grandparents I have not known). It is to my hygiene that I
  give the credit for having attained my 70 years in a satisfactory
  condition. I have taken no raw food for eighteen years and I
  introduce as many lactic bacilli as possible into my intestines. But
  it is but a first step; in spite of all, I am being poisoned by the
  bacteria of butyric fermentation. However, I have practically reached
  the normal term of life and I must be satisfied. I have, so to speak,
  accomplished the programme of a "reduced orthobiosis."

  When macrobiotics become more perfect, when people have learnt how to
  cultivate a suitable flora in the intestines of children as soon as
  they are weaned from their mother's breast, the normal limit of life
  will be put much further back and may extend to twice my 70 years.
  Then, also, satiety with existence will appear much later than it has
  done in my case.

  To-day they celebrated my jubilee at the Pasteur Institute, which
  touched me very much, in spite of my distrust of sentimental
  manifestations, for I realised their sincerity. I should have liked
  to set out a programme of the researches which should be accomplished
  by the Pasteur Institute, but I feared to detain my audience too long.

  I believe that Science will solve all the principal problems of Life
  and Death and that she will enable human beings to accomplish their
  vital cycle by real orthobiosis, not by a reduced caricature of it as
  in my case. Nevertheless, I consider the experiment practised upon
  myself as having already given some result and that is to me a real
  satisfaction.

  [32] _Annales de l'Institut Pasteur_, 1915.

We spent that summer a few weeks at Norka, where Metchnikoff completed
his researches concerning the death of the silk-worm moth.

We went for delicious walks; we spent all the afternoon by the lake
or under the pines in the heather, reading and working. Once only,
during a walk, he had a strong cardiac intermittence, but as a rule
he felt well. I could see, however, that he was obsessed by a grave
preoccupation which he did not express. Later, during his last illness,
he confessed to me that during the whole of that stay at St. Léger he
had feared to die suddenly during one of our walks. The thought of my
isolation weighed on his mind and he hid his anxiety so as not to alarm
me....

With a view to the work which he had planned on the sexual question,
he interested himself in the influence that their sentimental life had
had on the activity of great men, and we read together the biographies
of Beethoven, Mozart, and Wagner. Elie was more than ever desirous of
making our holidays as pleasant as possible, as if he already felt that
they were our last. Here are more extracts from his note-book:

                         ST. LÉGER-EN-YVELINES, _24th June 1916_.

  When saying that I did not fear death, I had in view the dread of
  annihilation. That fear, manifested during a long period of life
  and disappearing towards the end, may be compared with the fear of
  darkness which children instinctively feel and which also disappears
  gradually and naturally. When, towards the end of life, the fear of
  nothingness ceases, no desire remains for a future life, for the
  immortality of the soul. It would even be painful to me to think
  that the soul, surviving the body, could watch, from beyond, the
  misfortunes of those who remain on the earth. On the contrary,
  towards life's decline, a desire for complete annihilation becomes
  developed.

He spent the autumn collecting and preparing the materials he required
for his book on the sexual function. It was a relief from the sad
impressions of the war and the deserted laboratory. But new troubles
were in store for us; I became ill, and had scarcely recovered when we
heard the news of the death of a nephew who was very dear to us. The
death of the young had always deeply moved Metchnikoff, and it was so
in this case. It was another weight thrown into the already descending
scale.

In spite of all, he continued to work with enthusiasm, planting young
trees that future generations might enjoy their shade.




                             CHAPTER XXXVI

  Bronchial cold--Aggravated cardiac symptoms--Farewell to Sèvres
  --Return to the Institute--Protracted sufferings--Intellectual
  preoccupations--Observations on his own condition--The end--
  Cremation.


If in this sad last chapter I occasionally dwell on details which may
seem insignificant in themselves, it is because, at this supreme moment
of Elie Metchnikoff's existence, everything was full of significance,
for everything converged to emphasise the powerful unity and the
ascending and continuous progress of his ideas.

His attitude in the face of illness and death was a teaching, a
support, and an example. That is why, relating the story of his last
days, I piously describe everything.

Towards the end of November, he caught a slight cold, which did not
prevent him from leading his usual life, but which, nevertheless, was
the starting-point of the illness which took him from us.

On the 2nd of December, during a walk, he suddenly felt a cardiac
commotion such that he thought he was dying. For hours, his pulse
remained intermittent and very rapid, and from that day he felt unwell
but continued to go to the laboratory.

On the 9th of December his condition became worse and forced him to
interrupt his normal life. All the doctors were away or very busy on
account of the war, and it was only on the 11th that Dr. Renon could
give him a consultation at the Laënnec Hospital. He found Metchnikoff's
heart very tired and nervous, prescribed a treatment, and told us to
come back in twenty-five days.

But the disease was making giant strides. In the night of the 12th to
13th a first attack of cardiac asthma supervened, an extremely painful
one; we had the impression that the end was near. Elie suffered agonies
but remained morally calm and ready for death, as he had ever been
since his first heart attack, two years previously. He repeated that he
had accomplished his task and run through his vital cycle; that what he
could yet do would be but a supplement, and that it was better to die
than to outlive his own decadence.

He only wished not to suffer too long, but that humble desire was not
to be realised. We spent two more nights at Sèvres, terrible nights not
to be forgotten if one had centuries to live, and we then decided to go
to a nursing home in Paris, as it was imprudent to remain any longer
isolated as we were.

Having heard of Metchnikoff's illness, Dr. Roux offered to receive us
at the Pasteur Institute in a small lodging which was now free, the
house-physician who had occupied it having been killed.

Dr. Widal, in whom Metchnikoff had absolute confidence, came to
Sèvres on the 14th and found myocarditis. Thanks to an absolutely
incomprehensible phenomenon, Elie had suddenly ceased to realise the
rapidity of his pulse; he had 160 beats in a minute and only perceived
less than half; it was therefore easy to keep the truth from him.

After a last night of suffering we left our Sèvres nest, which we had
so loved. Leaning on my arm, he slowly walked through the little
garden and gazed for the last time at the home that we were leaving for
the unknown.... He looked worn and bent under the weight of suffering,
but he was quite calm, and his eyes, though firm and gentle, already
seemed to me to be looking very far away.

The automobile bore us slowly from Sèvres to the Pasteur Institute,
and we found ourselves in the small flat which had been inhabited by
the young doctor who had been killed in the war. He had only spent a
short stage of his life there. How long should we remain? And what road
should we take when we left it? We tried to smile, though our hearts
were terribly heavy, in order to cheer each other.

But, in the course of the day, we were surrounded by friends full of
solicitude, the tension relaxed, and we felt a growing sense of comfort
and security. No more nights of mortal dread and loneliness, with no
help at hand! That thought alone inspired courage and hope. In case of
need, I had only to send down to the next floor to ask for a doctor.

For a few days, Elie felt much better, perhaps on account of the mental
relief, but his heart was weak and his pulse extremely rapid. Drs.
Widal, Martin, Veillon, Salimbeni, and Darré came to see him every day;
during the whole of his long illness, they never ceased to show him the
most attentive and devoted care. They attempted by every means to save
him from pain, for, alas, they had no hope of curing him. Nothing was
neglected, and many still greater sufferings were spared him.[33]

  [33] For instance, Dr. Widal, very early in his illness, had
       advised a saltless diet, which caused the infiltration in
       the tissues to remain comparatively slight.

The war was an inexhaustible and passionately interesting subject
of conversation; Elie read a number of newspapers and listened with
avidity to every news from private sources. Often, too, scientific
questions were discussed, which continued to interest him intensely.
These talks were an invaluable relaxation.

Feeling infinitely grateful towards his medical advisers and friends,
he showed himself a most docile patient, following their prescriptions
with absolute punctuality. When his condition grew worse and he felt
no hope whatever of his recovery, he often used to say, "What is to be
done? the doctors can do nothing, for medicine is powerless. Unhappily,
it will remain so for a long time. Much work will have to be done to
rid humanity of the scourge of diseases. But, surely, one day science
will succeed in doing so; that will be chiefly through prophylaxis and
rational hygiene. There will also be a new science--the science of
death; it will be known how to make it less hard."

After lunch and a short sleep, he received the daily visit of his
friend Dr. Roux, with whom he talked in the full intimacy of friendship
and affection. He confided to him his apprehensions and desires, and
felt unlimited gratitude for his kindness to us, often saying to me,
with tears in his eyes, "I knew Roux was a kind man and a true friend,
but I see now that he is incomparable." Other friends also did their
utmost to serve him and to show their sympathy. He had the great joy
of feeling himself beloved and surrounded with an atmosphere of real
kindness. Many times he said to me, "Now, only, have I appreciated the
warm-heartedness of the French at its full value. Do not fail, in my
biography, to emphasise how deeply I feel it, and how grateful I am. I
want them to know it."

Yet all the care and devotion of which he was the object could neither
arrest the fatal progress of disease nor spare cruel suffering to him
who had thought of nothing but relieving the pains of others. All our
efforts were as flowers scattered over a tomb; he, poor tortured one,
was slowly, consciously sinking into it through the implacable logic
of Fate. From the beginning of his illness, he foresaw the issue; he
lived in constant expectation of death, on the threshold of which his
calm and serenity remained as unalterable as were his patience and
resignation.

After a temporary and comparative lull, which lasted until the end of
December, the disease began to progress again, and almost every week
brought a fresh alarming symptom. It was especially during the night
that the pain, treacherously, reappeared. After dropping asleep fairly
early, he would begin to breathe with difficulty and then awake in
an indescribable state of anguish; perspiration drenched his head,
neck, and chest, several towels often being required to dry him. His
breathing was hard; during bad attacks, the wheezing of his bronchial
tubes was terrifying.

He would sit up, his hands clenched, his face blue and contracted by
suffering, his darkened lips apart, his eyes dilated--the face of a
man on the rack. He gasped like a suffocating man; at last a tearing
cough supervened, followed by expectoration, and the attack gradually
subsided.

For a time we were able to relieve him without the use of narcotics. As
long as there was a ray of hope--not of recovery, but of a bearable
life and further work--he wished at all costs to avoid the influence of
narcosis. He breathed fumes of pyridin or ether, he smoked Escouflaire
cigarettes, and inhaled various other things. In order to sleep after
an attack, he ate a few biscuits, and I sprinkled his head with a
menthol solution, with which I damped his temples and forehead. That
eased him, and sometimes he slept again for a few hours.

But how many were the nights of insomnia and suffering! How many times
did he call for death as a deliverer, and say that he _resigned_
himself to live for my sake only!

And in spite of the martyrdom he endured, he always had gentle words,
a caress, a consolation even! He constantly returned to the thought
that he had nothing to complain of, that he had had a large share of
happiness and good fortune in having accomplished his task, and even
arrived at the development of the natural death-instinct.

All those who saw him every day knew that he was courageous and
patient, every one admired his serenity, but no one could realise the
_degree_ of his courage and patience, for no one had seen and lived
through those miserable nights.

Often, even, when asked how he was, he said "not bad!" after a terrible
night, saying to me afterwards in explanation, "Why grieve them, since
it cannot be helped?"

At the beginning of our stay in the Institute, he was not yet quite
bedridden. After his morning toilet, he would lie for some hours on a
sofa, reading almost continuously, newspapers, scientific reviews, and
many works in connection with the book he had planned on the sexual
function, of which he wrote only the introduction and a few lines of
the first chapter.[34]

  [34] He expounded the theory that ideas on the sexual function
       had been falsified through fear of venereal diseases at a
       time when people did not know either how to avoid or cure
       those diseases. He showed that the condemnation of a natural
       function by divers religions was based on that fear. He
       analysed the deplorable consequences of that, and set forth
       the necessity of returning to more wholesome ideas, more in
       conformity with nature and allowing the study and avoidance
       of many evils. He thought that, in this connection, a new
       direction should be given to the education of children
       and to marriage. He then examined the part played by the
       sexual function in the lives of men of genius and, with
       that object, read many biographies and literary works.
       During his illness he read books concerning Victor Hugo and
       Napoleon, J. J. Rousseau's _Confessions_ and even parts of
       the _Nouvelle Héloïse_.

Another question occupied him at that time, that of first-born
children. Certain data led him to think that men of genius were but
rarely the first-born of their parents, and he sought for every
possible information on the subject. In his constant desire to improve
life-conditions, he even thought that a demonstration of this fact
might have a desirable influence on the increase of population in
France after the war; if it were proved that the most successful
children are not the first-born, perhaps the system of having two
children only would be given up in order to have a chance of giving the
country a more capable population.

His reflections on the sexual questions led him to seek for
experimental means of studying gonorrhoea. He thought of inoculating
the gonococcus into the eye of new-born mice and entrusted M.
Rubinstein, the only worker left in the laboratory, with these
experiments. The latter began them and obtained encouraging results,
but he left Paris in the spring and the work remained unfinished.

Metchnikoff's mind never ceased to work unless interrupted by acute
pain; until the very end, his brain never failed him. He often used to
say how far he was from any mystic aspirations, and how sure he was of
remaining a rationalist until the end. And such was the case. Faithful
to himself, not even in the most painful moments did he feel a desire
to look for support outside the ideas and principles of his whole life.
Yet his soul was sad and full of care; the war grieved him utterly,
every newspaper he read renewed his sorrow. When a severe engagement,
Verdun for instance, was going on, he lost the little sleep he had, and
his agitation became painful.

He was deeply disillusioned by the Germans. Having always felt great
esteem for their scientific work, he had believed in their high
culture, and now he was absolutely disconcerted by the mentality which
they manifested during the war.

Neither could he understand how the war had been allowed to come
about. He thought it ought to have been avoided, and considered the
authorities guilty for not having done so. He said that nothing could
compensate the harm done by this insane butchery.

The deserted laboratories, the interruption of scientific work, filled
his soul with melancholy. For, he said, all the great, all the real
questions should have been solved by Science and were kept waiting....

He also had material worries, the war having brought great perturbation
in his affairs. The fate of his mobilised pupils preoccupied him
constantly. The least indisposition, however trifling, of those he
loved made him unhappy. His sensibility, which had always been very
marked, increased still more, and consumed him; it surely was one of
the causes that had worn his heart out. When already very weak and ill,
he constantly thought of giving pleasure to those who were with him; he
read innumerable reviews and periodicals, and would tell each friend
what he had found of particular interest to the latter, even when
speech was difficult to him. His gentleness and cordiality were most
touching during the whole of his illness, though he preserved his usual
outspokenness.... It seemed to me that this offended no one; they all
understood Elie now.

He sought a refuge from his sufferings in his own ivory tower; these
sufferings themselves were to him a source of observations. He
studied his body and his soul as he would have studied any subject
under experiment. Every day he wrote down his auto-observations, and
carefully read the diary which I kept for him.

During the whole of the winter he had ups and downs. Towards the end
of December the cough and respiratory symptoms increased, and at the
beginning of January he expectorated clots of blood, due to a passive
congestion of the right lung.

On the 19th January, some liquid appeared in the pleura on the same
side. Pleurisy persisted for a whole month and necessitated three
punctures. Every time we feared to tell him that the puncture was
necessary, but he received the news with complete coolness, saying that
he had always been in favour of radical measures.

After the third puncture, which took place on the 19th February, a
marked relief supervened, and the improvement lasted for some time; it
was the only moment when we saw a ray of hope.

Though keeping to his bed, he worked a great deal, read, and received
not only his friends but other visitors. At the beginning of March and
at the end of April he again expectorated blood, and the terrible,
tragical nights began again. Yet the days were fairly good.

During that period, he had the pleasure of seeing some of his pupils
again, and of receiving several Russian deputies and journalists. They
talked to him of political events, of the war, of the moral state of
Russia. All that interested him immensely; he plied them with the most
varied questions. It must be remembered that, before that interview, we
had lost all touch with Russia.

During the whole of May he again had ups and downs, but the progress of
the disease was indisputable.

Tachycardia was constant, urine more and more scanty, the swelling of
the legs never decreased, cough and oppression occurred frequently
even during the day. Elie awaited his seventy-first birthday with
impatience. Often during the night, after a painful attack, he would
count the days, hours, and minutes which separated him from that date.
At last it arrived. Here are the lines which he added to his notes on
that day:

  16th May. Against all expectation, I have lived until this day. I
  have reached my 71 years. My dream of a rapid death without a long
  illness has not been realised. I have now been bedridden for five
  months. After several crises of tachycardia, following upon a slight
  grippe with asthma, I had congestion of one lung with pleuritic
  exudate. Though some improvement followed after that, nevertheless I
  am tormented by fits of sweating followed by cough and oppression. I
  suffer chiefly in the night from those attacks; they provoke insomnia
  which can only be combated by pantopon.

  My psychical state is twofold. In one way, I should like to get well,
  but, on the other hand, I see no sense in living any longer. Illness
  has not provoked in me any fear of death, and I am more deprived than
  formerly of the joy of living. The reawakening of spring leaves me
  quite indifferent. There can be no question for me of that pleasure
  which convalescents often feel, nor indeed of any pleasure. To the
  despair that I feel in the face of medicine's powerlessness to cure
  the ills of my friends is added the feeling of its powerlessness
  towards my own illness. I think that my desire to recover and to
  continue to live is connected with practical causes.

  The war has compromised our finances, our income from Russia has
  practically disappeared. If I die, my wife may find herself in a very
  difficult situation. Given her lack of practical notions, that may
  lead to very sad results. Yet it is quite impossible to straighten
  our affairs before the end of the war and the re-establishment of
  normal conditions.

These were the last words he wrote in his book of notes; his hand had
become weak and trembling; he tired very soon, and henceforth I wrote
under his dictation. On the 18th June, one month before his cremation,
he dictated to me for the last time, and this is what he said:

  This is the seventh month that I have been ill and it brings my
  thoughts back to the gravity of my condition. I therefore continually
  realise how much satisfaction I have derived from life during my long
  years. The gradual disappearance of my "life-instinct," which already
  began a few years ago, is now more marked, more precise. I no longer
  feel that degree of pleasure which I felt only a few years ago. My
  affection for my nearest and dearest shows itself much more by the
  anxiety and suffering provoked by their diseases and sorrows than by
  the pleasure I derive from their joys or normal health.

  Those to whom I describe my feelings tell me that satiety with living
  is not normal at my age. To that I oppose the following: Longevity,
  at least to a certain point, is hereditary. Now I have already
  mentioned, on the occasion of my 70th anniversary, that my parents,
  sister, and brothers died before reaching my present age. I knew
  neither of my grandparents, which shows that they could not have been
  very old when they died.

  Let us now turn to the profession, since it is an established fact
  that it has an influence on the duration of life. Pasteur died at 72,
  but for a long time he had been unable to do scientific work. Koch
  did not reach the age of 67. Other bacteriologists died at a much
  earlier age than I (Duclaux, Nocard, Chamberland, Ehrlich, Büchner,
  Loeffler, Pfeiffer, Carl Fraenkel, Emmerich, Escherich).

  Among those bacteriologists of my generation who are still living the
  majority have already ceased from working. All that should indicate
  that my scientific life is over and confirm at the same time the fact
  that my "orthobiosis" has actually reached the desirable limit.

He was anxious to prove that his end, which seemed premature at first
sight, did not contradict his theories, but had deep causes such as
heredity and the belated introduction of a rational diet. He had only
begun to follow it at fifty-three. Facts corroborated him after his
death, for the post-mortem examination showed that the heart lesions
were of long standing. He himself thought they went back at least to
1881, when he had had a very grave relapsing fever. The doctors even
wondered how he had lived with his heart in such a state, and only
accounted for it by the strict régime which he had followed during the
latter part of his life.

And indeed when it is remembered how pugnacious, how vehement he
was--always, so to speak, in a state of ebullition, feverishly active,
intensely sensitive--it must be admitted that his life really held more
than an ordinary life of longer duration.

He was very desirous that the example of his serenity in the face of
death should be encouraging and comforting. It should prove that, at
the end of his vital cycle, man fears death no longer; it has lost its
sting for him.

Early in June his condition became still worse. The nights were so
painful that, every evening, recourse had to be had to pantopon.[35] It
was with the greatest impatience that he awaited his "dear Darré and
dear Salimbeni," as he called them.

  [35] Pantopon is a narcotic drug prepared from opium.

After Dr. Darré had finished his complete and thorough medical
examination, we three remained talking around Elie's bed for a short
hour. He often recalled his personal or scientific memories when he was
not too weary; we talked of the war, of medical questions; often, too,
we would evoke, with Salimbeni, recollections of our journey to the
Kalmuk Steppes.

We loved that peaceful hour, which ended by an injection of pantopon,
the only relief, alas, that could be procured for him. He would thank
Dr. Darré with gratitude, and drop his poor weary head on the pillow,
awaiting in absolute security the blessed sensation of warm heaviness
which pervaded him, for he knew that sleep and rest from his sufferings
would not be long in coming. The spectre of tragical nights never
ceased to haunt us.

Until the hot weather came, he was quite comfortable in the small flat
in the Pasteur hospital; the temperature there had been perfectly
regular all through the winter; but now he began to be incommoded by
the heat.

M. Roux then proposed that we should be transferred to Pasteur's old
flat; the rooms were spacious and much cooler. This idea rejoiced and
touched Elie very much. As he thanked M. Roux, he said to him: "See
how my life is bound with the Pasteur Institute. I have worked here
for years; I am nursed here during my illness; in order to complete
the connection I ought to be incinerated in the great oven where our
dead animals are burnt, and my ashes could be kept in an urn in one
of the cupboards in the library." "What a gruesome joke!" answered M.
Roux, really taking those words for a joke. But directly after he was
gone Elie turned to me with an anxious look and said, "Well, what do
you think of my idea?" I saw by his earnest expression that he meant
what he said, and I answered that I thought it a very good idea.
The Pasteur Institute had become his refuge, the centre of all his
scientific interests; he loved it; he had spent his best years there.
Let his ashes be laid there some day; it would be in perfect harmony
with his past. Let us only hope that would not be too soon! But why had
he given his words that jesting form which must have misled M. Roux? He
explained it to me: knowing how deeply conscientious his friend was,
he did not wish to express his desire as a dying wish in order that he
should feel no obligation. A simple jest, on the contrary, left him
absolutely free.

On the 26th June, Elie was carried into Pasteur's flat; it was a very
great satisfaction to him, it brought him nearer his laboratory. Now
and then, very seldom now, he thought he might return there one day;
he said I should wheel him there in his bath-chair. "I know I could
scarcely work there myself. But perhaps I might still play the part of
a ferment, be useful to my pupils by giving them advice. I am leaving
so much unfinished work which it would be interesting to go on with:
the question of intestinal flora, that of diabetes, which surely
is an infectious disease--but that will have to be proved,--and my
experiments on the subject were scarcely begun. I think the study of
gonorrhoea will give very interesting results when they succeed in
inoculating it in new-born animals. And the question of tuberculosis is
well started! I could still help my pupils and encourage them if I were
a little better!... But I have no illusions! I must live now only from
day to day...."

Those words were uttered with heart-rending resignation.

He continued to get worse....

It was fortunate that pantopon should have given him good nights, for
attacks of oppression now supervened several times during the day;
tachycardia was continuous, the heart was weakening. The quantity of
urine diminished; it often did not surpass 250 cubic centimetres, and
no diuretic succeeded in increasing it; the legs remained swollen,
ascitis was beginning to become visible; in the night he occasionally
grew slightly delirious.

At the beginning of July he wished to sit up; he spent part of the
afternoon in an armchair, his legs lying on cushions. We thought it
was a good sign, but in reality he found it difficult to breathe lying
down. Several times he asked me to play to him, very soft music, as
noisy sounds wearied him. I played him some Beethoven, some Mozart;
the last time it was a Chopin prelude.

On the 9th his temperature went down in an alarming way to 35.2° C.
(95 F.). For the first time he would not write down his ordinary
observations. "What is the good?" said he, "it has no longer any
interest." Yet the next day he did so, for the last time. On the 11th
and 12th he put down his temperature, and glanced superficially at the
notes I had written. On the 12th, about five o'clock in the morning, he
had a bad fit of breathlessness followed by coughing, and brought up
large clots of very red blood. He smiled faintly. "You understand what
that means," he said, adding some tender words.

I wheeled him to his bed, which he never left again.

On the 13th, in the early morning, he felt very ill. Calmly and gently
he warned me to be ready. "It will surely be to-day or to-morrow."

My heart breaking, I asked him why he said that; was he feeling very
weak? or suffering very much?

"No," he said, "it is difficult to say what I feel; I have never felt
anything like it; it is, so to speak, a death-_sensation_.... But I
feel very calm, with no fear. You will hold my hand, will you not?"

How can I describe those last three days? He preserved all his lucidity
and serenity, often smiling at me and drawing me towards him. He
inhaled oxygen very often, as breathlessness became almost continuous.

On the 14th there was to be a _matinée_ performance of _Manon Lescaut_,
and remembering that his god-children had long wished to see that
opera, he had had a box taken for them. He was now quite uneasy about
it. "What ill-luck," he said, "if _it_ happened just before and
prevented them from going. In any case they must not come here on their
way to the theatre, so that if _it_ happens they will not know, and can
still enjoy the performance."

Thanks to pantopon, he spent a very good night. He awoke about five
o'clock, but remained so quiet that I thought him asleep. When I rose
about six he held out his hand to me and told me he had been awake for
a long time. He talked to me tenderly, in the full intimacy of our
affection; he spoke sweet, unforgettable words. He made me promise once
again not to give way to grief. "At first, our friends will help you,
and then work, that infallible remedy, and duty.... You will have that
of writing my biography. Remember how much I wish the _last_ chapter to
be complete. You alone can write it, for you have seen me all the time;
I have told you all my thoughts, and yet...." I understood that he had
occasionally, out of pity for me, hidden his sufferings and his sad
thoughts. But he did not know how often I guessed what he did not say;
love and pain have a dumb language, more eloquent than any human words.

"You will hold my hand when the moment comes," he repeated. "But do
not think I am afraid, now that it is near. No, I assure you, I have
an absolute serenity of soul! I spent a divine night. It seemed to
me that I was already half outside life. This night has taught me
many things.... Everything which troubled me, everything that seemed
so disturbing, so terrible, like this war for instance, seems so
transitory now, such a small thing by the side of the great problems of
existence!... Science will solve them some day." He ceased speaking. He
seemed illumined by a very exalted feeling; it was like the last chord
of his harmonious soul. What a consolation if he could have died then!

But life is cruel. He lived through two more days of suffering. On
the 14th he inhaled oxygen almost continually. He asked for pantopon,
but we feared to give him too much. I told him it would induce such
continuous sleep that he would not even be able to enjoy it. "But an
eternal sleep is precisely what I want! Do understand that now nothing
is left to me but pantopon. What is the good of making me last? Is
this a life? A few days or a month have no importance when one is not
going to recover. And you cannot wish to prolong my sufferings." His
breathlessness increased; he said, "Give me your hand; stay near me!" I
knew what he meant; he had the "death-sensation."

His poor hands were hot and warmed my cold ones.... The next day I
could not warm his hands, ice-cold for ever.

The whole day he awaited with impatience the hour for pantopon. About
nine o'clock, when Dr. Darré came in, he said, "Dear Darré, at last!"

There was no talk that evening, he was so weary. With what anguish I
awaited the stroke of midnight, which ended those two dread days! He
had been mistaken by barely one day. The night was not bad, in spite
of breathlessness and some fits of coughing. The next morning he felt
better. He had not read the papers the day before, to-day I read him
the communiqués in the _Petit Parisien_, he said it was enough. He also
turned the pages of a book he had recently begun to read, _La Science
et les Allemands_.

I told him how pleased I was to see him better. "It is true," he said,
"to-day I have no death-sensation, but I beg you, have no illusions!"

Always that preoccupation of breaking the shock for me. He made me
bring a pocket-book with some money in it and a few envelopes; in each
of them he made me place notes of similar value, then with his already
shaking hand, he himself wrote on each envelope the value of the notes
multiplied by their number, and explained that it was to help me to
find quickly what I should require after the catastrophe.

He ate better at lunch than he had done lately; but already at two
o'clock the breathlessness increased. Yet he did not look pale; he had
preserved his rosy complexion. As he inhaled the oxygen, he was shaken
by a hiccough. He pressed my hand. "It is the end," he said, "the death
rattle; that is how people die." He looked at his watch on the small
table, it marked four o'clock.

"No," he said, "it must have stopped. Four o'clock struck some time
ago." And he smiled. "Is it not strange that it should have stopped
before I? Go and see what time it is."

I ran out to see the clock from the window of another room; it was
twenty minutes to five. I met some one in the passage and asked him to
go quickly to fetch one of the Institute doctors. Then I begged Elie
not to have such ideas, and tried to cheer him.

"But, my child, why do you want to calm me? I am quite calm; I am only
stating facts," he said, adding tender words.

At that moment Salimbeni came in. Elie said to him: "Salimbeni, you are
a friend; tell me, is it the end?" And as he protested, he added, "You
remember your promise? You will do my post-mortem? and look at the
intestines carefully, for I think there is something there now." MM.
Roux and Martin then arrived. The feeling of weight in the intestines
of which he complained was mentioned. He did not know that he had
ascitis in the peritoneum.

As I was attending to him I felt him move suddenly, and said, "I beg
you, do not make such sudden movements; you know it is not good for
you." He did not answer. I raised my head; his was thrown back on the
pillows, his face had assumed a blue tinge, the white of the eyes alone
could be seen under the half-closed lids.

Not a word, not a sound.

All was over.[36]

  [36] It was 5.20 by the conventional war time, 4.20 in reality.

Then an abyss of oblivion....

I saw him again, stretched on his deathbed. He was white, cold, and
dumb. His face bore a calm and very serious expression. He looked like
a martyr who had at last entered into rest. Death had marked his face
with no dread seal. The lids had closed of their own accord, and he
seemed to be sleeping after great lassitude; one might have thought
that, with his usual kindness, he wished to spare us all too painful an
impression....

All through the night and the next morning his face preserved the same
expression.

In the afternoon Salimbeni performed the autopsy. Then he was laid in
his coffin; twenty-four hours had elapsed since the end. Wrapped in a
white sheet, which framed his fine face, he had the appearance of a
biblical prophet.

Now his expression had assumed absolute serenity, illumined by
gentleness and kindness. He had a look of elevation, grandeur, and
beauty which was really divine. It was an apotheosis. His beautiful
soul beamed in its full purity; neither suffering nor any earthly
preoccupation had any hold on it. He gave an impression of eternal rest.

It was his final image, a splendid one, the last ... for ever.

The bier was closed and covered with a heavy black pall. On life also a
blacker and heavier pall had fallen. The light had gone out.

Two days later, on the 18th July, he was carried to the cemetery of
the Père Lachaise, to be cremated in all simplicity, as he had wished.
Faithful to his ideas, he had wished for a lay funeral, with no
speeches, flowers, or invitations.

His bier disappeared into a large sarcophagus; on each side black
curtains fell to hide what was going on.... Then one hour of heavy
silence whilst the poor body was being consumed by the flames....

A death silence....

And that was all....

The mercurial, vivacious child, good-hearted, intelligent, and
precocious; the young man, ardent, impetuous, passionate, a lover of
science and of all that was exalted; the mature man, a bold thinker,
an indefatigable investigator, eager, generous, tender, and devoted;
the old man, in everything faithful to himself, but progressing in
serenity, shining with an ever softer light, like a mountain peak in
the setting sun; the martyr at last, enduring suffering with patience
and resignation, seeing the approach of death without fear, observing
it as he had observed life....

The hour of silence was over; the incineration accomplished. Of his
body, little was left--a handful of ashes. They were enclosed within an
urn and placed in the library of the Pasteur Institute.

But his beautiful, ardent soul, his audacious and fertile ideas, all
that rich inner life which had developed into a harmonious and puissant
symphony, all _that_ cannot be dead, cannot disappear! The ideas, the
influence we give to life must persist, must live; they are the sacred
flame which we hand on to others and are eternal.




                               EPILOGUE


The life and work of Elie Metchnikoff are so intimately bound together
that, in a biography, it is impossible to separate them. That is why
the description of his work necessarily has been dispersed along the
story of his life; but, just as, in order to judge of a work of art,
one has to draw back and contemplate the whole, we must also, after
following the evolution and successive stages of E. Metchnikoff's
scientific works, take a full view of his work as a whole.

He was a born biologist; everything connected with life interested
him. In his childhood, he observed plants and animals. At the age of
fifteen, he became acquainted with microscopic beings; they aroused in
him such powerful interest towards the primitive forms of life that,
from that moment, not only his future path was marked out for him but
also his method of starting from the simple to elucidate the complex.
He was imbued with Darwin's theory of evolution; having begun by the
study of inferior animals, he began to look for their connections with
other groups.

He endeavoured to establish the continuity and the unity of phenomena
in all living beings. According to his method of studying first what
was simplest, he turned to embryology, for in the egg and the embryo
it is possible to follow step by step the transformation of the
simple to the complex and to see the origin and development of all the
constituent parts of the organism. Moreover, the embryo is exempt from
secondary complications, due to the multiple external conditions of
post-embryonic life.

Metchnikoff was able to establish, from embryological data, that the
development of lower animals takes place according to the same plan
and under the same laws as that of higher animals. In all of them,
the segmentation of the egg is followed by the formation of embryonic
layers, of which each gives birth to cells and to definite organs.
Superior forms repeat, in their embryonic life, the evolution cycle of
inferior forms.[37]

  [37] Thus the _parenchymella_, _phagocytella_, and _gastrula_
       stages correspond in the embryo with the adult form of
       certain very primitive Metazoa and even to a colony of
       unicellular animals.

This common plan in the embryology of all animals established their
genealogical continuity and strengthened the Darwinian theory.

Metchnikoff's studies, carried out on the various groups of animals,
contributed towards the foundation of comparative embryology. Owing to
the comparative method, he had made himself familiar not only with the
morphological and functional continuity of divers organisms, but also
with that of their constituting cells; a comparison between the latter
and unicellular beings was inevitable. That is why, having ascertained
that the mobile cells of the lower Metazoa absorbed foreign bodies by
inclusion, he naturally concluded that that phenomenon was similar to
digestion in unicellular beings.

Having established the fact of intracellular digestion in lower
animals, he extended it to certain cells of the higher animals; thus
his phagocyte theory was born.

Seeing that unicellular beings, like the mobile cells of Metazoa,
englobe, not only food, but foreign bodies, he asked himself whether
this was not at the same time a defensive action. Such a possibility
brought no surprise to a zoologist, accustomed to see that, in the
struggle for existence, animals often devoured their enemies.

All the materials for the building up of the phagocyte theory were
therefore ready in Metchnikoff's mind when he asked himself, as by an
intuition, whether the white globules of our blood, globules so similar
to amoebæ, do not play the part of a defensive army in our organism
when they envelope in accumulated masses intrusive bodies injurious to
the organism.

The thought was but the result of a preparatory work already
accomplished; it was the butterfly escaping out of the chrysalis.

Metchnikoff had recourse to his method of simplification in order to
solve the question.

The organism of the higher animals being extremely complicated, he went
down as far as the transparent larva of the starfish (bipinnaria) in
order to watch with his own eyes the phenomena which take place within
it. He introduced a rose-thorn into the transparent body of the larva,
and noted the next day that the mobile cells in the latter had crowded
towards the splinter, like an army rushing to meet a foe.

The analogy of this phenomenon with inflammation and the formation
of an abscess was striking. Metchnikoff said to himself that since
most diseases in the higher animals are accompanied by inflammation
and provoked by microbes, it was chiefly against these microbes that
our defensive cells had to struggle. He named the defensive cells
_phagocytes_.

He confirmed his hypothesis by another observation, equally simple. In
a little transparent crustacean (Daphnia) infected by a small parasitic
fungus, (_Monospora bicuspidata_), he was easily able to observe the
struggle between the animal's mobile cells and its parasites.

These two simple observations served as foundation and supports to the
bridge by which Metchnikoff connected normal biology with pathological
biology. Having entered the domain of the latter, he studied various
microbian diseases, and asked himself why the organism was sometimes
liable and sometimes refractory. In order to elucidate this question,
he turned again to lower animals, in which he could easily observe the
most intimate phenomena, simplified.

He ascertained that liability in an animal corresponded with the fact
that microbes introduced into the organism remained free and invaded
it, whilst immunity coincided with the inclusion and digestion of the
microbes by phagocytes.

He also found that, in artificial immunity, the phagocytes are
accustomed gradually, by preventive inoculations, to digest microbes
and their toxins.

Thus he established the fact that phagocytosis and inflammation are
curative means employed by the organism.

All his ulterior researches, his studies on the various categories of
phagocytes and their properties, on their digestive liquids, on the
formation of antitoxins, on the different properties acquired by the
blood, etc., were but the natural development of those premises.

He had proved that the part played by the phagocytes consists, not only
in the struggle against microbes and their poisons, but also in the
destruction of all the mortified or enfeebled cells of the organism,
and that atrophies are nothing more than the absorption of cellular
elements by the phagocytes.

He found that senile atrophies have the same cause, and asked why the
cells of old people's organisms should become enfeebled.

He demonstrated that the principal cause is the chronic poisoning
of the cells by toxins manufactured by microbes in the intestine.
Premature senility was the result--a phenomenon as pathological as any
disease.

The source of the evil, therefore, resides in the intestinal flora.
Accordingly he started to study the latter, as also senility, in order
to find means of struggling against both.

His researches enabled him to indicate a series of means, based, on the
one hand, on the struggle against microbes, and, on the other, on the
defence of the noble cells against destructive ones.[38]

  [38] Replacement of the wild and noxious flora of the intestines
       by antagonistic cultivated microbes; strengthening and
       vaccinating of noble cells.

The study of old age led him to that of syphilis, a disease which
provokes an arterio-sclerosis which is similar to that of old people;
the study of the normal intestinal flora was followed by that of
intestinal diseases, such as typhoid fever and infantile cholera.

Finally, he progressed towards the last phenomenon, the most mysterious
in nature, Death.

Researches on the silk-worm moth--a rare example of an animal the life
of which ends in natural death--allowed him to conclude that the latter
is due to an auto-intoxication of the organism.

But he only just raised the veil of the great mystery; it was his last
work....

       *       *       *       *       *

Metchnikoff's philosophical evolution ran on parallel lines with his
scientific researches.

When studying the laws and the unity of vital phenomena he found that
their harmony was occasionally broken by the collision of internal
conditions with the environment and that regrettable consequences
ensued. He saw an example of that in human nature, full of disharmonies
due to its animal origin.

These considerations caused the pessimism of his youth. But his
energetic, pugnacious temperament could not remain content with a
passive acceptance of facts.

He started to study the lack of harmony in human nature and its causes,
and sought for means to combat these causes. Gradually he reached the
conclusion that the greatest human disharmonies are provoked by the
rupture of the normal cycle of our life, by the precocity of senility
and of death, chiefly arising from a chronic poisoning by the toxins of
intestinal microbes.

But having acquired the conviction that it is possible to struggle
against that intoxication, he concluded that science, which has already
done so much to fight diseases, would also find means of struggling
against _premature_ old age and _precocious_ death, thus leading us to
the normal vital cycle, _orthobiosis_.

Then disharmony, transformed into harmony, will cause the greatest of
ills to disappear.

Faith in the power of Science and in the possibility of modifying human
nature itself through Science was the foundation of the optimistic
philosophy of his maturity. Thoughts full of strength and hope shine
like leading stars all along his philosophical works.

"Alone, Rational Science is capable of showing humanity the true path."

"The real goal of human existence consists in an active life in
conformity with individual capacity; in a life prolonged until the
appearance of the _death-instinct_, and until Man, satisfied with the
duration of his existence, feels the desire for annihilation."

"Man is capable of great works; that is why it is desirable that
he should modify human nature and transform its disharmonies into
harmonies."

"If an ideal capable of uniting _men_ in a sort of religion is
possible, it can only be founded on scientific principles. And, if it
is true, as is often affirmed, that man cannot live without faith, it
must be faith in the power of Science."

Thus Elie Metchnikoff had begun by the study of nascent life in
inferior beings; by a logical and continuous chain, he had followed the
whole cycle of development of living beings in their continuity and
their whole.

From the initial question of intracellular digestion he had reached the
most exalted problems which can occupy our minds, the harmonising of
human discords through knowledge and will.

Such is the harmonious edifice which he has built.

No vital question was indifferent to him. He tackled the most difficult
and most mysterious among them with courage, moved by an invincible
impulse towards Truth and sustained by enthusiasm and faith in the
power of Science.

The beauty of a work of art consists in the harmony and unity of a
realised conception.

Thus a Gothic cathedral, by its graceful and harmonious lines,
expresses an impulse towards higher spheres; it leans solidly on the
earth only in order to soar better towards the heavens.

Such is also the character of Elie Metchnikoff's life-work.




                       BIBLIOGRAPHICAL APPENDIX


                       WORKS OF ELIE METCHNIKOFF

  1865. "Beiträge zur Kenntniss der Chaetopoden," Zeitschrift für
           wissenschaftliche Zoologie, xv. 3, p. 328.

        "Über einige wenig bekannte Thierformen," Zeit. f. wissen.
           Zool. xv. 4, p. 450.

        "Über Geodesmus bilineatus Nob. (Fasciola terrestris), eine
           europäische Landplanarie, Mélanges biologiques" (Bull. de
           l'Académie des Sciences de Saint-Pétersbourg, vol. v.).

  1866. "Untersuchungen über die Embryologie der Hemipteren
           (vorläufige Mitteilung)," Zeit. f. wissen. Zool. xvi. 1, p.
           128.

        "Zur Entwicklungsgeschichte von Myzostomum," Zeit. f. wissen.
           Zool. xvi. 1, p. 326.

        "Apsilus lentiformis, ein Räderthier," Zeit. f. wissen. Zool.
           xvi. 3, p. 1.

        "Embryologischen Studien an Insecten," Zeit. f. wissen.
           Zool. xvi. Entgegnung auf die Erwiederung des Her. Prof.
           Leuckart in Giessen, in Betreff der Frage über die
           Nematodenentwicklung (Göttingen, Verlag von Adalbert Rente).

  1867. "Beiträge zur Naturgeschichte der Würmer," Zeit. f. wissen.
           Zool. xvii. 4, p. 539.

        "Embryology of the Sepiola" (in Russian), Archives des Sciences
           physiques et naturelles, Genève, vol. 21.

  1868. "Beiträge zur Kenntniss der Entwicklungsgeschichte der
           Chaetopoden" (in collaboration with Ed. Claparède), Zeit. f.
           wissen. Zool. xviii.

  1869. "Embryology of Nebalia" (in Russian), Mélanges biologiques
           de l'Académie de Saint-Pétersbourg, vi. p. 730.

        "Untersuchungen über die Metamorphose einiger Seethiere,
           Tornaria," Zeit. f. wissen. Zool. xx. p. 131.

        "Über ein Larvenstadium von Euphausia," Zeit. f. wissen. Zool.
           xix. 4, p. 179.

        "Über die Entwicklung der Echinodermen und Nemertinen,"
           Mémoires de l'Acad. de Saint-Pétersbourg, xiv. 8, p. 33.

  1870. "Bemerkungen über Echinodermen," Bulletins de l'Acad. de
           Saint-Pétersbourg, xiv. p. 51.

        "Embryologie des Scorpions," Zeitschr. f. wissen. Zool. xxi.

  1871. "Über die Metamorphose einiger Seethiere," Zeit. f. wissen.
           Zool. xxi. 2, p. 235.

        "Entwicklungsgeschichte des Chelifers," Zeit. f. wissen. Zool.
           xxi. p. 513.

        "Über den Naupliuszustand von Euphausia," ibid. Bd. xix.

  1872. "Zur Entwicklungsgeschichte der einfachen Ascidien," Zeit.
           f. wissen. Zool. xxii. 3, p. 339.

        "Vorläufige Mitteilung über die Embryologie der Polydesmiden,"
           Mélanges biologiques des Bullet. de l'Académie des Sciences
           de Saint-Pétersbourg, vol. viii.

        "Zur Entwicklungsgeschichte der Kalkschwämme," Zeit. f. wissen.
           Zool. xxiv. p. 1.

        "Studien über die Entwicklung der Medusen und Siphonophoren,"
           Zeit. f. wissen. Zool. xxiv. p. 15.

        "Embryologie der doppelfüssigen Myriapoden," Zeit. f. wissen.
           Zool. xxiv. p. 253.

  1874. "Embryologisches über Geophilus," Zeit. f. wissen. Zool.
           xxv. p. 313.

  1876. "Beiträge zur Morphologie der Spongien," Zeit. f. wissen.
           Zool. xxvii. p. 275.

  1878. "Spongiologische Studien," Zeit. f. wissen. Zool. xxxii. p.
           349.

  1879. "Spongiologische Studien," Zeit. f. wissen. Zool. xxxii. p.
           374.

  1880. "Über die intracelluläre Verdauung bei Coelenteraten,"
           Zoologischer Anzeiger, No. 56, p. 261.

        "Untersuchungen über Orthonectiden," Zeit. f. wissen. Zool.
           xxxv. p. 282.

        "Über die systematische Stellung von Balanoglossus,"
           Zoologischer Anzeiger, pp. 139, 153.

  1881. "Zur Lehre über die intracelluläre Verdauung niederer
           Tiere," Zoologischer Anzeiger, p. 310.

        _Vergleichend-embryologische Studien_:

        1. Entodermbildung bei Geryoniden.

        2. "Über einige Studien der Cunina," Zeit. f. wissen. Zool.
           xxxvi. p. 433.

  1882. 3. "Über die Gastrula einiger Metazoen," Zeit. f. wissen.
           Zool. xxxvii. p. 286.

        "Die Embryologie von Planaria polychroa," Zeit. f. wissen.
           Zool. xxxviii. 3, p. 331.

  1883. "Untersuchungen über die intracelluläre Verdauung bei
           wirbellosen Tieren," Arbeiten d. zool. Instituts zu Wien, v.
           2, p. 14 (Quarterly Journal of Micr. Science, vol. 93).

        "Untersuchung über die mesodermalen Phagocyten einiger
           Wirbeltiere," Biologisch. Centralblatt, No. 18, p. 560, Bd.
           iii.

  1884. "Embryologische Mitteilungen über Echinodermen,"
           Zoologischer Anzeiger, vii. Nos. 158, 159.

        "Über eine Sprosspilzkrankheit der Daphnien; Beitrag zur Lehre
           über den Kampf der Phagocyten gegen Krankheitserreger,"
           Virchow's Archiv, vol. 96, p. 177.

        "Über die Beziehung der Phagocyten zu Milzbrandbacillen,"
           Virchow's Archiv, vol. 97, p. 502.

        "Über die pathologische Bedeutung der intracellulären
           Verdauung," Fortschritte der Medizin, 1884, p. 558, No. 17.

  1885. _Vergleichend-embryologische Studien_:

        4. "Über die Gastrulation und Mesodermbildung der Ctenophoren,"
           648.

        5. "Über die Bildung der Wanderzellen bei Asterien und
           Echiniden," Zeit. f. wissen. Zool. xlii. p. 656.

  1886. "Medusologische Mittheilungen," Arbeiten d. zool. Instituts
           zu Wien, vi. 2, p. 1.

        Embryologische Studien an Medusen, ein Beitrag zur Genealogie
           der Primitivorgane, Wien, 1886.

  1887. "Sur l'atténuation des bactéridies charbonneuses dans le
           sang des moutons réfractaires," Annales de l'Institut
           Pasteur, i. p. 42, No. 1.

        "Über den Kampf der Zellen gegen Erysipelkokken, ein Beitrag
           zur Phagocytenlehre," Virchow's Archiv, vol. 107, p. 209.

        "Über den Phagocytenkampf bei Rückfalltyphus," Virchow's
           Archiv, vol. 109, p. 176.

        "Sur la lutte des cellules de l'organisme contre l'invasion des
           microbes," Annales de l'Institut Pasteur, i. p. 321, No. 7.

        "Kritische Bemerkungen über den Aufsatz des Herrn
           Christmas-Dirckinck-Holmfeld, I. V.," Fortschritte der
           Medizin, 17, p. 541.

  1888. "Über die phagocytäre Rolle der Tuberkelriesenzellen,"
           Virchow's Archiv, vol. 113, p. 63.

        "Pasteuria Ramosa, un représentant des bactéries à division
           longitudinale," Annales de l'Institut Pasteur, p. 165, t.
           ii. No. 4.

        "Über das Verhalten der Milzbrandbakterien im Organismus,"
           Virchow's Archiv, vol. 114, p. 465.

        "Réponse à la critique de M. Weigert au sujet des cellules
           géantes de la tuberculose," Annales de l'Institut Pasteur,
           ii. p. 604.

  1889. "Recherches sur la digestion intracellulaire," Annales de
           l'Institut Pasteur, iii. p. 25, No. 1.

        "Contribution à l'étude du pléomorphisme des bactéries,"
           Annales de l'Institut Pasteur, iii. p. 61, No. 2.

        "Note sur le pléomorphisme, etc.," Annales de l'Institut
           Pasteur, iii. p. 265, No. 5.

        _Studies on Immunity_:

        1. "Immunité des lapins contre le bacille du rouget des porcs,"
           Annales de l'Institut Pasteur, iii. p. 289, No. 6.

  1890. 2. "Le Charbon des pigeons," Annales de l'Institut Pasteur,
           iv. p. 65, No. 2.

        3. "Le Charbon des rats blancs," Annales de l'Institut Pasteur,
           iv. p. 193, No. 4.

  1891. 4. "L'Immunité des cobayes vaccinés contre le Vibrio
           Metchnikowii," Annales de l'Institut Pasteur, v. p. 465, No.
           8.

        "Sur la propriété bactéricide du sang de rat" (in collaboration
           with Dr. Roux), No. 8.

        "Recherches sur l'accoutumance aux produits microbiens" (in
           collaboration with Dr. Roudenko), Annales de l'Institut
           Pasteur, v. p. 567, No. 9.

        "Beiträge zur vergleichenden Pathologie der Entzündung,"
           Virchow Festschrift, vol. 11.

  1892. "La Phagocytose musculaire" (in collaboration with Dr.
           Soudakevitch), Annales de l'Institut Pasteur, vi. p. 1.

        Leçons sur la pathologie comparée de l'inflammation. Paris,
           1892.

        "On Aqueous Humour, Micro-organisms and Immunity," Journal of
           Pathology, i.

        _Studies on Immunity_:

        5. "Immunité des lapins vaccinés contre le microbe du
           Hogcholéra," Annales de l'Institut Pasteur, vi. p. 189, No.
           5.

        "Atrophie des muscles pendant la transformation des
           batraciens," Annales de l'Institut Pasteur, vi. No. 1.

        "Note au sujet du mémoire de M. Soudakevitch (Parasitisme
           intracellulaire des néoplasmes cancéreux)," No. 3.

        "Über Muskelphagocytose," Centralblatt für Bakteriologie, 1892.

        "La Lutte pour l'existence entre les diverses parties de
           l'organisme," Revue scientifique, 10 sept. 1892, No. 11.

  1893. "Recherches sur le choléra et les vibrions, 1er mémoire"
           (Sur la propriété préventive du sang humain vis-à-vis du
           vibrion de Koch), Annales de l'Institut Pasteur, vii. p.
           403, No. 5.

        2. "Mémoire," idem (Sur la propriété pathogène des vibrions),
           tome vii. p. 562, No. 7.

        Comparative Pathology of Inflammation. Lectures at the Pasteur
           Institute. Paul: London, 1893. 8vo. (The name of the
           translator is not stated.)

  1894. 3. "Mémoire," idem (Sur la vaccination artificielle du
           vibrion cholérique), Annales de l'Institut Pasteur, viii. p.
           257, No. 5.

        4. "Mémoire," idem (Sur l'immunité et la réceptivité vis-à-vis
           du choléra intestinal), tome viii. p. 529, No. 8.

        "L'état actuel de la question de l'immunité" (Rapport du
           Congrès international de Budapest), Annales de l'Institut
           Pasteur, viii. p. 706, No. 10.

  1895. _Studies on Immunity_:

        6. "Sur la destruction extracellulaire des bactéries dans
           l'organisme," Annales de l'Institut Pasteur, ix. p. 433, No.
           6.

  1896. "Toxine et antitoxine cholériques" (in collaboration with
           Drs. Roux and Salimbeni), Annales de l'Institut Pasteur, x.
           p. 25, No. 5.

        "Quelques remarques à propos de l'article de Gabritchevsky sur
           la fièvre récurrente," Annales de l'Institut Pasteur, x. No.
           11.

        _Recherches sur l'influence de l'organisme sur les toxines_:

  1897. 1st Memoir. "Recherches sur l'influence de l'organisme sur
           les toxines," Annales de l'Institut Pasteur, xi. p. 801.

        "Réponse à M. Gabritchevsky," Annales de l'Institut Pasteur,
           xi. No. 3.

        "Immunität," Weyl's Handbuch der Hygiene. Jena, 1897.

        "Recherches sur l'influence de l'organisme sur les toxines"
           (Communication faite au congrès de Moscou en août 1897),
           Annales de l'Institut Pasteur, xi. No. 10.

  1898. 2nd Memoir. "Influence du système nerveux sur la toxine
           tétanique," Annales de l'Institut Pasteur, xii. No. 2, p. 81.

        3rd Memoir. "Toxine tétanique et leucocytes," Annales de
           l'Institut Pasteur, xii. No. 4, p. 263.

  1899. "Résorption des cellules," Annales de l'Institut Pasteur,
           xiii. No. 10, p. 737.

  1900. _Researches on the Influence of the Organism on Toxins_:

        4ème mémoire. "Sur la spermotoxine et l'antispermotoxine,"
           Annales de l'Institut Pasteur, xiv. p. 5.

        "Sur les cytotoxines," Annales de l'Institut Pasteur, xiv. No.
           6. p. 369.

        "Recherches sur l'action de l'hémotoxine sur l'homme," Annales
           de l'Institut Pasteur, xiv. No. 6, p. 402.

  1901. _Biological Studies on Old Age_:

        1st Memoir. "Sur le blanchiment des cheveux et des poils,"
           Annales de l'Institut Pasteur, xv. No. 12, p. 865.

        L'Immunité dans les maladies infectieuses. Paris, 1901.

  1902. _Biological Studies on Old Age._ "Recherches sur la
           vieillesse des perroquets" (in collaboration with Drs.
           Mesnil and Weinberg), Annales de l'Institut Pasteur, xvi.
           No. 12.

        The Nature of Man. Studies in optimistic philosophy. The
           English translation by P. Chalmers Mitchell. Heinemann:
           London; Putnams: New York, 1903. 8vo.

  1903. _Studies on Human Nature_: Paris, 1903.

        Études expérimentales sur la syphilis (in collaboration with
           Dr. Roux):

        1st Memoir. Annales de l'Institut Pasteur, xvii. No. 12, p. 809.

  1904. 2nd Memoir. "Études expérimentales sur la syphilis" (in
           collaboration with Dr. Roux), Annales de l'Institut Pasteur,
           xviii. No. 1, p. 1.

        3rd Memoir. Id. No. 11.

  1905. 4th Memoir. Id. Annales de l'Institut Pasteur, xix. No. 11.

        Immunity in Infective Diseases. Translated from the French by
           F. G. Binnie. University Press: Cambridge; The Macmillan
           Co.: New York, 1905. 8vo.

  1906. 5th Memoir. Id., Annales de l'Institut Pasteur, xx. No. 10.

        The New Hygiene: three lectures on the prevention of infectious
           diseases. Translated and a preface written by E. Ray
           Lankester. Heinemann: London, 1906. 8vo.

        [Another edition.] Chicago Medical Book Co.: Chicago, 1906. 8vo.

  1907. [Another edition.] W. T. Keener & Co.: Chicago, 1907. 8vo.

        "Sur la prophylaxie de la syphilis" (Paper read at the XIIth
           International Congress in Berlin), Annales de l'Institut
           Pasteur, xxi. No. 10.

        The Prolongation of Life: optimistic studies. The English
           translation edited by P. Chalmers Mitchell. Heinemann:
           London, 1907. 8vo.

        _Essais optimistes._

  1908. "Études sur la flore intestinale," "Putréfaction
           intestinale," Annales de l'Institut Pasteur, xxii. No. 12.

  1909. Idem. "Roussettes et microbes" (in collaboration with MM.
           Weinberg, Pozersky, Distaso, Berthelot), Annales de
           l'Institut Pasteur, xxiii. No. 12.

        Notes on Sour Milk and other Methods of administering Selected
           Lactic Germs in Intestinal Bacterio-therapy. J. Bale, Sons &
           Co.: London, 1909. 8vo.

  1910. Idem. "Poisons intestinaux et scléroses," Annales de
           l'Institut Pasteur, xxiv. No. 10.

        The Prolongation of Life. New and revised edition, Heinemann:
           London; Putnams: New York, 1910. 8vo.

  1911. "Sur la fièvre typhoïde expérimentale" (Metchnikoff et
           Besredka), Annales de l'Institut Pasteur, xxv. No. 3.

        Annales de l'Institut Pasteur:

        Tome xxv. No. 6. Quelques remarques sur la vaccination à propos
           du mémoire de M. Choukevitch sur le choléra.

        Tome xxv. No. 6. Réponse de MM. Metchnikoff et Besredka à M. le
           Dr. Vincent (remarques sur la vaccination antityphique).

        Tome xxv. No. 11. El. Metchnikoff, E. Burnet et L.
           Tarassevitch, "Recherches sur l'épidémiologie de la
           tuberculose dans les steppes Kalmouks."

        Tome xxv. No. 12. El. Metchnikoff et A. Besredka, "Des
           vaccinations antityphiques (2nd Memoir)."

  1912. Tome xxvi. No. 11. El. Metchnikoff et Eug. Wollman, "Sur
           quelques essais de désintoxication intestinale,"
           "Bactériothérapie intestinale."

        The Warfare against Tuberculosis--being the Priestley Lecture
           of the National Health Society for the year 1912. Published
           in Bedrock, January 1913. Constable: London.

  1913. _Études sur la flore intestinale._

        Tome xxvii. No. 8. "Des vaccinations antityphiques" (El.
           Metchnikoff et A. Besredka).

        Tome xxvii. No. 11. "Toxicité des sulfoconjugués de la série
           aromatique."

  1914. Tome xxviii. No. 2. "Études sur la flore intestinale" (4ème
           mémoire). "Les diarrhées des nourrissons."

  1915. Tome xxix. No. 8. "Causerie de El. Metchnikoff à l'occasion
           de son jubilé."

        Tome xxix. No. 10. "La Mort du papillon du mûrier."

        "Founders of Modern Medicine: Pasteur, Lister, Koch" in Russian
           (a French translation to appear shortly).

  1915-16. "Introduction à 'Études sur la fonction sexuelle'"
           (posthume, dans Le Mercure de France, 1917).

  1916. The Nature of Man. Popular edition. Heinemann: London, 1916.
           8vo.

  _Note._--Sources consulted: British Museum Catalogue; English
           Catalogue; American Catalogue.




                                 INDEX


  Acoelomata, development of, 73

  Albaran, Dr., 231

  Alexander I., Tsar of Russia, 26

  Alexander II., 28;
      assassination of, 101, 104, 218

  Alexis Michailovitch, Tsar, sends Spatar on mission to China, 24;
      death of, 25

  Alhambra, the, 124

  Amour (Amur) river, Spatar's exploration of, 24

  _Anisoplia austriaca_, experiments on, 111

  _Annales de l'Institut Pasteur_, 1915, 249-50 _n._

  Anthrax vaccine experiment, unfortunate result of, 133-4

  Anthropoid apes, Metchnikoff's desire to experiment with, 140, 189;
      syphilis experiments with, 190, 191;
      infantile cholera experiments with, 207, 220;
      typhoid fever experiments with, 207

  Antitoxins, Metchnikoff's experiments with, 162

  _Arbeiten des zool. Inst. zu Wien_, publication of Metchnikoff's
    "Untersuchung über die intracelluläre Verdauung bei wirbellosen
    Tieren," 119 _n._

  Arterio-sclerosis, 189, 206

  Ascidia, Metchnikoff's difference with Kovalevsky _re_, 62, 73

  Asiatic cholera, 220

  Astrakhan steppes, 84, 85

  Austria, declaration of war on Serbia, 1914, 240


  Baer, Prof., and Baer Prize, 58

  Bakounine, 52, 56

  Bardach, Dr., 127, 133

  Bassarab, Constantine, 24

  Baumgarten, Prof., hostile criticism of phagocyte theory, 126, 129;
      criticism refuted, 148

  Behring, theory of immunity, 148;
      discovery of antitoxins, 149, 150

  Békétoff, Prof., 40, 58

  _Bell_, the, 29

  Berlin Congress, 1890, 148-9

  Berthelot, M., pupil and collaborator of Metchnikoff, 197, 221

  Besredka, Dr., researches, 161-2, 207-8

  Birsch, 169 _n._

  Bobrinsky, Count, 111, 112

  Bogomoloff, 29

  _Bombyx mori_ (moth of the silk-worm), Metchnikoff's experiments
    with, 238-9, 251

  Bordet, M. I., important researches and experiments, 165

  Borrel, M., 162

  Brockhaus and Effrone, _Encyclopædia_ quoted, 25-6

  Bronn, _Classes and Orders of the Animal Kingdom_, 31

  Büchner, 169, 265;
      paper on humoral theory, 150

  Buckle, _History of Civilisation_, 29

  Buda-Pest Congress (International, 1894), 159

  _Bulletin of the Moscow Society of Naturalists_, 33

  Bunsen, 48

  Burnet, M., 211


  Caillaux affair, 240

  Cantemir, Prince, 26

  Casso, Minister of Public Instruction, 219

  Cephalopoda, Metchnikoff's study of, 56, 57

  Chamberland, 265

  Chauveau, 169 and _n._

  Cholera outbreak in France, 1892, 154;
      Metchnikoff's experiments with cholera vibrio, 154-7, 158 _seq._

  Choukevitch, Dr., 212

  Cienkovsky, friendship for and interest in Metchnikoff, 59, 60, 73;
      resigns from Odessa University, 75;
      bacillus, 210

  Claus, Prof., 48, 119

  Coelentera and intracellular digestion, 107, 110, 116

  Coelomata, development of, 73

  Cohendy, M., research work of, 196

  Cohn, association with and interest in Metchnikoff, 43, 45

  "Conception of Nature and of Medical Science, A," Metchnikoff's
    Stuttgart Lecture, 1909, 209, 224

  Crimea, and Black Sea fauna, 59

  Ctenophora, 73

  "Curative Forces of the Organism, The," Metchnikoff Lecture on, in
    Berlin, 1908, 208, 223

  Curded milk, manufacture, Metchnikoff's connection with, 226-7


  Daphniæ, experiments with, 121, 279

  Darré, Dr., 256, 266, 271

  Darwin, _The Origin of Species_, 41;
      theories, 276, 277

  Diabetes, 246

  Dubois-Reymond, journal of, 48

  Duclaux, M., 137, 265

  Duniasha (Avdotia Maximovna), 4, 10


  Eberth's bacillus, 207-8

  Echinodermata, Metchnikoff's researches, etc., 61, 62, 70;
      metamorphoses of, 72, 73;
      and intracellular digestion, 107, 110, 116;
      observations on larvæ transformation, 119

  _Education from an Anthropological Point of View_, Metchnikoff's
    paper on, 63, 74

  Ehrlich, Prof., 199, 265

  Embryology, comparative, Metchnikoff's studies in, 50-51, 56, 57,
    107, 277

  Emmerich, 265;
      attack on phagocyte theory, 131;
      attacks refuted, 148

  Engelmann, 45

  Ephemeridæ, Metchnikoff's study of, 105, 106, 193, 237

  Escherich, 265

  _Essais optimistes_, 191-2, 209

  _Études sur la nature humaine_, 185, 191, 209;
      quoted, 188

  Evolution, Metchnikoff's researches in, 50-51


  _Fabricia_, Metchnikoff's researches on, 43

  Fédorovitch, Mlle. Ludmilla, afterwards Madame Elie Metchnikoff, 63;
      engagement to Metchnikoff, 65-9;
      marriage to Metchnikoff, 69;
      illness of, 69-70;
      a clever draughtswoman, 71;
      temporary recovery of, 73;
      relapse, 74, 75, 78;
      death, 79

  Fédorovitch, Mlle., 71, 74, 78, 80;
      account of interview with Metchnikoff, 83

  "Flora of the Human Body," Wilde Lecture, 1901, 182

  _Flore du corps humain_, La, 224

  "Forces curatives de l'organisme," quoted, 120-21

  _Forty Years' Search for a Rational Conception of Life_, 223

  _Founders of Modern Medicine, The_, extract from preface to, 247-8

  Fraenkel, Carl, 265


  Gamaléia, Dr., 127, 133

  Garibaldi Movement, the, 47

  Garnier, M., 21, 22

  _Gastræa_, Haeckel's theory of the, 108

  "Gastrotricha," Metchnikoff's establishment of, 42

  Geneva, young revolutionary centre, 47-8

  _Geodesmus bilineatus_, 106-7

  Geophilus (_see_ Myriapoda)

  George, Henry, 202

  Germany, Metchnikoff's appreciation of scientists of, 55

  Germany, declaration of war on Russia, 240;
      on France, 242

  Giessen, Naturalists' Congress at, 1864, 44-5

  _Glycobacter peptonicus_, 221, 222

  Goethe, _Faust_, 195, 204

  Goldschmidt, Dr., 78, 79

  _Göttingen News_, Leuckart's memoir on Nematodes in, 48

  Granada, 124

  Gravitz, 169 _n._

  Grove, _The Unity of Physical Forces_, 32

  Guancios, Caves of the, 77


  Haeckel, theory of the _gastræa_, 108

  Hayem, 169 _n._

  Heitz, Dr., 231

  Heligoland, flora and fauna of, 43

  Helmholtz, 48

  Henle, Prof., 54

  Herzen, _Passé et pensées_, 47

  Hirschfeld, 169 _n._

  Hodounof, 19, 20, 22

  Hueppe, Prof., 131

  Hugo, Victor, 260 _n._


  Iamanouchi, M., 211

  Immunity, 122;
      opposing theories of Behring and Metchnikoff, 148, 149, 150, 151;
      ancient and modern theories of, 168-70;
      Metchnikoff's exposition of, 171-180

  _Immunity in Infectious Diseases_, 170

  Infantile cholera, 207, 220-21

  _Inflammation_, Metchnikoff's lectures on, 152-3

  Intestinal flora, problem of, 196-8, 206;
      further researches, 220, 235, 280;
      experiments with rats, 221, 222

  Intracellular digestion, Metchnikoff's studies of, 57, 105, 107, 110,
    116, 170, 277, 278


  Jaurès, assassination of, 240

  Jelly-fish, Metchnikoff's monograph on embryology of, 126

  Jenner and method of antivariolic vaccination, 168

  _Journal de Moscou_, Elie Metchnikoff's first publication in, 33

  Jupille, M., 155


  Kalmuk steppes, Metchnikoff's journey to, 82-3;
      description of, 215-16;
      Metchnikoff's anthropological work among natives of, 84-5;
      liability of natives to tuberculosis, 210-11;
      Pasteur Institute expedition to, 212;
      description of, 215-17

  Keferstein, Prof., 54

  Kent, Saville, discoveries of _Protospongia_, 110

  Kharkoff, 1, 16, 20;
      Lycée, progress in, 28;
      University, ancient methods in, 31-2, 37, 40

  Kherson, peasants' grievances and vexatious conduct in, 113, 114

  Kirghiz steppes, endemic plague in, 211;
      Russian plague mission to, 211, 215, 218;
      description of, 214

  Kleinenberg, Prof., encouragement of Metchnikoff, 118, 119

  Kleps, 169 _n._

  Koch, Prof., 265;
      attitude to Metchnikoff's theory, 133, 149

  Kölliker, Prof., 37

  Kovalevsky, Alexander, friendship with Metchnikoff, 49, 58;
      work of, 51, 52, 61, 62, 72, 73, 108;
      divides Baer Prize with Metchnikoff, 58

  Kriloff, 26

  Kühne, 41


  Latapie, M., 155

  _Law of Life, The_, 223

  _Leçons sur la pathologie comparée de l'inflammation_, 152-3

  Leube, Dr., 231

  Leuckart, Prof., 43-5, 46

  Lilienfiorse, 199

  Lister, Dr., 148

  Loeffler, 265

  London Congress, 149-50

  Lubarsch, attacks on Metchnikoff's theory, 232

  Lucernaria, 73


  _Macaques_ or Barbary apes, 124;
      Metchnikoff's typhoid experiments with, 207-8

  Macrophages, 163-4, 166, 178, 184

  Madeira, 75

  Maeterlinck, Maurice, 228-9

  Maisonneuve, M., 191

  Malaga, gardens of, 124

  Manoukhine, Dr., 231

  Martin, Dr., 256, 273

  Medusæ, 72, 73, 116

  Mertens, 76, 79

  _Messenger of Europe_, Metchnikoff's contributions to, 208-9,
    239 _n._

  Messina, Metchnikoff's work at, 61

  Messina, the Metchnikoff home at, 115

  Messina, earthquake at, 1908, 115, 116

  Metazoa, 277

  Metchnikoff, Dmitri Ivanovitch, devotion to his brother's family, 5,
    17, 21, 28;
      appearance and character, 5-6;
      other references, 12, 14

  Metchnikoff, Elie (or Ilia), parents' home at Panassovka, 1-3;
      birth of, 3;
      appearance and disposition in childhood, 8-11;
      early indications of unusual intelligence, 9, 16, 20;
      an adventurous journey to Slaviansk, 12-15;
      life at Kharkoff, 16-18;
      develops natural history tastes with Hodounof, 20-22;
      ancestry, 23-7;
      entry into and progress at Kharkoff Lycée, 28-34;
      friendships and their influence, with Bogomoloff, 29,
          with Tschelkoff, 32-3, 42,
          with Kovalevsky, 48 _seq._,
          with Cienkovsky, 59-60,
          with Kleinenberg, Virchow, and others, 118-19,
          with Pasteur, 132 _seq._,
          various, 56, 58-9, 63, 65, 93, 137;
      adopts atheism and shows continued interest in natural history,
        29-30;
      love of music, 31, 34, 54-5, 93;
      plans a scientific career, 31;
      early publications, 33, 41;
      devotion to his mother, 35, 93-4;
      early love affairs, 35-6;
      abortive journey to Würzburg, 37-9;
      at Kharkoff University, 40-42;
      an early controversy with Kühne, 41;
      influenced by Darwin, 41, 50;
      early researches and privations in Heligoland, 43-5;
      letters to his mother quoted, 44-6, 65-9;
      at Giessen Congress, 45;
      work and relations with Leuckart, 45-8;
      eyesight troubles, 46, 62, 82-3, 105;
      visit to Geneva, 46-8;
      researches, Mediterranean, 48-53, 56-7, 61 _seq._,
          in the Crimea, 59-60,
          at Spezzia, etc., 70-73,
          anthropological among Kalmuks, 84-5,
          in intracellular digestion and Ephemeridæ, 105-11, 116,
          in infectious diseases, 128,
          in tuberculosis and phagocytosis, 133;
      at Pasteur Institute, 135-6,
          in cholera, 154-157,
          in immunity, 168-80,
          in senile atrophies and intestinal flora, 182-9, 191, 196-8,
            206-8, 220 _seq._,
          in syphilis, 189-91,
          in infantile cholera and typhoid, 207-8, 220,
          in tuberculosis and plague among Kalmuks, 210-19;
      silk-worm moth, 238-9, 251;
      contribution to foundation of comparative embryology, 51, 56;
      studies in Germany and opinion of German scientists, 54-5, 57;
      illnesses, 55-56, 65, 104, 181, 217, 222, 229 _seq._, 249;
      return to Russia and Odessa University appointment, 58-60;
      appointed Zoology Professor at Petersburg, 61;
      interest in educational questions, 63, 100;
      life at Petersburg, 63-4, 71 _seq._;
      engagement and first marriage, 66-70;
      reappointed to Odessa University and difficulties of appointment,
        73, 75, 78, 98 _seq._;
      his philosophical theory and its evolution, 74-7, 184-9, 191-5,
        209, 222-4, 228-9, 281-3;
      visit to and life at Madeira, 75-7;
      death of first wife, 79;
      attempts suicide, 80-81;
      Mlle. Fédorovitch's description of, 83;
      journey to Astrakhan steppes, 82-3;
      studies of childhood, 86;
      meeting with family of second wife and growing intimacy, 86-8, 94;
      Setchénoff's description of, 88;
      harmony of second marriage, 89-95;
      character and disposition 96-8, 143-5;
      views of women's scientific capacity, 103;
      inoculates himself with relapsing fever, 104;
      and the phagocyte theory, first statement of, 110,
          describes first inception of, 116-17,
          progress in, 117-22, 126, 128, 142, 148, 150-53, 158-66,
            183, 208-9,
          controversies and attacks on, 131, 133, 142, 147-9;
      difficulties over Russian estate management, 112-14;
      life at Messina, 115-19;
      again returns to Russia, 119;
      journey through Spain to Tangiers, 123-4;
      life at Tangiers and Villefranche, 125-6;
      describes work at Bacteriological Institute, Odessa, 127-8;
      describes first meeting with Pasteur, 132;
      Pasteur's offer, 132;
      visit to Berlin and reception by German scientists, 133;
      work and influence at Pasteur Institute, 135-146;
      M. Roux's appreciations of, 138-9, 150, 159;
      other appreciations, 141, 165;
      life at Sèvres and Paris, 144-5;
      visit to England, 149;
      triumph at London Congress, 150;
      interest in Pfeiffer's phenomenon, 158-60;
      theory and studies of natural death, 192-5, 230-35, 237-8, 252;
      receives Nobel Prize, 199;
      journey to Sweden and Russia, 199-200;
      visit to Tolstoï, 200-205;
      expedition to Kalmuk steppes, 210 _seq._;
      unpleasant incident of lacto-bacilli fabrication, 225-7;
      kindness to friends, 227-8;
      descriptions of his own symptoms, etc., 229-36, 250-51, 263-5;
      holidays at St. Léger-en-Yvelines, 228, 237-9, 251;
      effect of war on, 239-46, 261;
      preface to _Founders of Modern Medicine_ quoted, 247-8;
      plans a work on sexual questions, 249, 252, 260;
      jubilee celebrations, 249-50;
      last illness, 254-73;
      last days at Pasteur Institute, 256-73;
      death, 273;
      synopsis of work and achievements, 276-81

  Metchnikoff, Madame, meeting with Metchnikoff, 87,
      parents and family, 87-8, 94,
      marriage, 89, 90,
      relations between husband and wife, 90-95,
      illness of, in 1880, 104,
      loss of both parents, 112,
      illnesses of, 123, 181, 252

  Metchnikoff, Emilia Lvovna (_née_ Nevahovna), appearance and
    disposition, 2, 5, 6, 93;
      a capable housewife, 3;
      a devoted mother, 4, 6, 13, 14, 18, 37;
      delicacy of, 22;
      ancestors, 26;
      influence on Elie Metchnikoff's choice of a career, 41;
      endeavours to prevent Elie's first marriage, 66;
      letters to, from Elie quoted, 44-5, 65-69;
      death of, 94

  Metchnikoff, Elena Samoïlovna, 4, 8, 10

  Metchnikoff, Ilia Ivanovitch, home at Panassovka, 1,
      appearance and character, 2,
      marriage, 2,
      easy-going temperament, and extravagance, 2-6,
      attitude to his family and servants, 6-7

  Metchnikoff, Ivan, 3, 8

  Metchnikoff, Katia, appearance and character, 8,
      marriage, 16, 21,
      other references, 12, 14

  Metchnikoff, Leo, 3, 8,
      illness of, 19,
      gifted but superficial nature of, 19, 46-7;
      activities in Geneva and connection with Garibaldi Movement,
        46-7, 80

  Metchnikoff, Nicholas, birth of, 3;
      appearance, 8;
      his great-aunt's favourite, 8, 10;
      boyhood pursuits, 17-18;
      enters Kharkoff Lycée, 28;
      life in Kharkoff, 31;
      death of, 230

  _Microphages_, 163-4, 166

  Morosoffs, the, of Moscow, 189

  Moscow, Anthropological Society of, Metchnikoff's report to, 85

  Moscow, International Congress, 1897, 164-5;
      Skin Disease Research Society, 189

  Müller, Fritz, _For Darwin_, 50

  _Müller's Archives_, Metchnikoff's memoir on the Vorticella in, 41

  Myriapoda, embryology of, 76, 85


  Naegeli, 169 _n._

  Naples, cholera epidemic in, 1865, 53;
      Metchnikoff's first stay at, 49-53,
      second stay, 62

  Napoleon, 260 _n._

  Natural death, Metchnikoff's studies of, 237, 280-81

  Natural science, Metchnikoff's campaign for the teaching of, 100

  Nematodes, Metchnikoff's discoveries, etc., 42, 46

  Nevahovitch, Leo, 26

  Nicholas I., 28

  Nobel Prize, the, 199

  Nocard, M., 265;
      appreciation of Metchnikoff, 165

  Norden, Dr., 231


  Odessa, University of, 58-9,
      Metchnikoff's work at, 60-61, 98-9,
      party intrigues at, 75, 101,
      rights to autonomy threatened, 101-3,
      Congress, 1883, 120,
      bacteriological Institute founded at, 127

  Oldenburg, Prince of, 129


  Panassovka, the home of the Metchnikoffs, 1, 3,
      fire at, 20-21

  _Parenchymella_, explanation of, 109-110

  Paris, International Congress, 1900, 170

  Paris, air raids on, 246

  Pasteur, antirabic inoculations, 127,
      Metchnikoff's first interview with, 132,
      friendship with Metchnikoff and interest in phagocyte theory, 137,
      experiments in vaccination and immunity, 168-9,
      death of, 181,
      discovery of lactic fermentation microbe, 193,
      age at death, 265

  Pasteur Institute, the, 132,
      Metchnikoff's work and influence at, 134-142, 144,
      Metchnikoff's appreciation of, 139,
      effect of outbreak of European War on, 244-5;
      celebration of Metchnikoff's jubilee, 249

  Peter the Great, Tsar of Russia, 24, 25, 26

  Petersburg, 2, 19,
      Congress of Russian Naturalists at, 1867, 60-61,
      difficult conditions of Metchnikoff's work at, 63-4, 71,
      foundation of Bacteriological Institute at, 129

  Petersburg Geographical Society, 82

  Petrushka, 4, 12, 13

  Pettenkoffer, 154, 236

  Pfeiffer, 265,
      experiments in extracellular destruction of microbes, 158-60,
        165-6, 175;
      attacks on Metchnikoff's theory, 232

  _Phagocytella_, 110, 126

  Phagocytes, origin of Metchnikoff's theory of, 51, 57, 278,
          development of theory, 110, 111, 113, 120-22, 142,
          inception of theory, 116-19,
          Baumgarten's hostile criticism of theory, 126;
      application of theory to erysipelas, 128,
          opposition to theory, 131, 151,
          controversy, 148,
          renewed experiments for proving theory, 148, 149, 150, 151,
            152, 153, 279;
      vindication of, at Buda-Pest Congress, 159, 160;
      experiments with toxins and poisons, 160-62;
      experiments with antitoxins, 162-164,
          and doctrine of immunity, 170-80,
          and senility, 183, 280

  Phagocytosis, Metchnikoff's first paper on, read at Odessa Congress
    of Physicians and Naturalists, 1883, 120

  _Phyllirhoë_, 175

  Picot, E., _Chronicle of John Neculua_ quoted, 23

  Pirquet's test, 211

  _Pleomorphism of Microbes_, Metchnikoff's memoir, 1888, 211

  Poland, Revolution in, 1830, 26

  Polypi, 72

  _Popular Star_, 29

  Preyer, theory of fatigue and sleep, 194

  _Protospongia_, discovery of, by Saville Kent, 110

  Pushkin, 2, 26


  Radlkoffer, _The Crystals of Proteic Substances_, 33

  Rasputin, 219

  Recklinghausen, 169 _n._

  Relapsing fever, experiments to prove phagocytic reaction, 129

  Renon, Dr., 255

  Rotifera, 193, 237-8

  Rousseau, J. J., _Confessions and the Nouvelle Héloïse_, 260 _n._

  Roux, Dr., 137, 255,
      appreciation of Metchnikoff quoted, 138-9, 141, 159, 249;
      collaboration with Metchnikoff, 150, 162, 163, 164,
      wins Osiris Prize, 189;
      reply to campaign against Metchnikoff, 226;
      friendship with and visits to Metchnikoff in his last illness,
        257, 267, 273

  Rubinstein, M., 260


  St. Léger-en-Yvelines, 228, 237

  Salimbeni, Dr., 163, 184, 211, 215, 256, 266, 272-3

  Sanarelli, Dr., discovery of choleriform bacilli, 156

  Sarepta, 217-18

  Schaudinn, discovery of syphilitic treponema, 190

  Scorpion, the, Metchnikoff's researches concerning the development
    of, 71

  Senility and death, Metchnikoff's views on and researches, 182-8,
    191-5

  Serums, their action, 177

  Setchénoff, Prof., 52-3, 71, 73, 78, 239;
      autobiography quoted, 88

  Sèvres, Metchnikoff Villa at, 144, 145

  Siphonophora, 72

  Slaviansk, adventurous journey of the Metchnikoff family to, 12

  Spain, Metchnikoff's eventful journey through, 80

  Spatar, Joury Stepanovitch, 26

  Spatar, Nicholas Milescu, exploits and adventures of, 23-4,
      mission to China, 24,
      literary activities and services to Peter the Great, 25,
      death of, 25

  Spezzia, the Metchnikoffs sojourn at, 70-71

  Sponges and Echinodermata, Metchnikoff's study of, 61, 72, 106, 117

  Stepanita, Prince, his dealings with Nicholas Milescu Spatar, 24

  Syphilis, Metchnikoff's researches on, 189-91, 280


  Tangiers, journey to, through Spain, 123-4,
      description of, 124-6

  Tarassevitch, Dr., 212

  Tchistovitch, Dr., 231

  _Time for Marriage, The_, Metchnikoff's paper on, 77

  Tolstoï, Léon, a day at Iasnaïa Paliana, 200-205

  Tolstoï, Countess, 203

  Tornaria, Metchnikoff's discovery concerning, 70

  Toxins and the phagocyte theory, experiments, 160 seq.

  _Trattoria della Harmonia_, the, 53

  Trieste, Metchnikoff's work at, 62

  Tschelkoff, Prof., 32, 33, 40, 41, 42

  Tshori, Convent of, 217

  Tuberculosis, researches on phagocytosis, in, 133;
      Metchnikoff's theory of natural vaccination, 210-11, 218

  Typhoid fever, 207-8


  Vaquez, Dr., 230

  Veillon, Dr., 256

  Vienna, Hygienists' Conference at, 1887, 131

  Villa Orotava, giant dragon-tree at, 77

  Virchow, cellular theory, 32, 48, 169 _n._;
      encouragement of Metchnikoff, 118-19;
      _Archives_, publication of Metchnikoff's researches in, 122, 129

  Volga, description of, 212-13

  von Noorden, 182

  von Siebold, Prof., 54

  Vorticella, the, Metchnikoff's memoir on, 41


  Waldeyer, 169 _n._

  Weinberg, M., 184

  Widal, Dr., 255, 256

  Wollman, pupil and collaborator of Metchnikoff, 196-7, 221

  Würzburg, University of, Metchnikoff's abortive journey to, 37


  Zalensky, 32


                                THE END




_Printed in Great Britain by_ R. & R. CLARK, LIMITED, _Edinburgh_.




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      "Sagesse"; Middle Age; The Last Phase; Verlaine's Literary
      Position.


  VERLAINE. By WILFRED THORLEY. (Modern Biographies Series. See p. 9.)


  PAUL BOURGET. By ERNEST DIMNET. (Modern Biographies Series. See p. 9.)


  VICTOR HUGO. By MARY DUCLAUX. (Makers of XIX. Century Series. See p.
    4.)


  CARDUCCI. By ORLO WILLIAMS. (Modern Biographies Series. See p. 9.)


  DANTE ALIGHIERI: A Biographical Study. By CHARLES A. DINSMORE.

                                            Large Crown 8vo. 15s. net.

      "Dante's latest biographer has made out a very just summary of
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  THE LIFE OF TOLSTOY. By AYLMER MAUDE.

    Vol. I. First Fifty Years to 1870.

    Vol. II. Later Years.

                   Each vol. illustrated. Price per vol. 12s. 6d. net.


  TOLSTOY. By EDWARD GARNETT. (Modern Biographies Series. See p. 9.)


  JOHANN SEBASTIAN BACH. His Life, Art, and Work. Translated from the
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    CHARLES SANFORD TERRY, LITT.D.

                                      Illustrated. Demy 8vo. 21s. net.

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  TSCHUDI, THE HARPSICHORD MAKER. By WILLIAM DALE, F.S.A.

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  MICHEL-ANGELO: A Record of his Life as told in his own Letters and
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  LIFE AND LETTERS OF LAFCADIO HEARN. By ELIZABETH BISLAND.

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  LAFCADIO HEARN. By EDWARD THOMAS. (Modern Biographies Series. See p.
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  THE JAPANESE LETTERS OF LAFCADIO HEARN. By ELIZABETH BISLAND.

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                                 IV.

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  THE LIFE OF ELIE METCHNIKOFF. By OLGA METCHNIKOFF. Translated by Mrs.
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                                               Frontispiece. Demy 8vo.

      Reviewing the French edition of this book in January 1921, _The
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      human being who conceived so many ideas, who developed so many
      theories, inventions, innovations.... Mme. Metchnikoff has made
      us admire the man of science and warmly the man."


  THE LIFE OF PASTEUR. By RÉNÉ VALLERY-RADOT. Translation by Mrs. R. L.
    DEVONSHIRE. New Edition with a preface by Sir WILLIAM OSLER, Bart.,
    M.D., F.R.S. 2nd edition.

                                     Demy 8vo. Portrait. 10s. 6d. net.

      "A classic of scientific biography."--_Saturday Review._

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      "Pasteur's career is set out in the fullest detail, making an
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      France and of science."--_The Times Literary Supplement._


  SIR VICTOR HORSLEY. By STEPHEN PAGET. Foreword by LADY HORSLEY.

                                      Illustrated. Demy 8vo. 21s. net.

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      "No biographer who agreed with Horsley could have given us
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      has excelled himself."--_The Observer._


  LIFE AND LETTERS OF JOSEPH BLACK, M.D. By Sir WILLIAM RAMSAY, K.C.B.,
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  ROBERT BOYLE: A Biography. By FLORA MASSON.

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    Revised and Abridged.

                                Illustrations. Demy 8vo. 12s. 6d. net.

      "The life story of Sir Charles Bright presents the career
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      scientific progress of this century.... These volumes possess a
      special interest for men of science, but they tell with clearness
      and simplicity the career of a man of whom Englishmen must always
      feel proud."--_Morning Post_.

                                                      [_Spring 1921._]


MESSRS. CONSTABLE will be glad to send free on application classified
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Transcriber's note:

Variations in spelling and hyphenation have been retained except in
obvious cases of typographical error.

Names and terms which deviated between chapter headings and text have
been made consistent.