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.