EVOLUTION AND SPONTANEOUS GENERATION
By many biologists, even at the present day, the origin and evolution of
living beings is considered to be outside the domain of natural phenomena,
and hence beyond the reach of experimental research. The change in our
views on this subject is due to a Frenchman, Jean Lamarck, who was the true
originator of the scientific doctrine of evolution. At a time when the
miraculous origin of every living being was regarded as an unchangeable
verity, and was defended like a sacred dogma, Lamarck boldly formulated his
theory of evolution, with all its attendent consequences, from spontaneous
generation to the genealogy of man.
In his _Philosophie Zoologique_, which appeared in 1809, Lamarck put forth
his claim to regard all the phenomena of life, of living beings, and of man
himself as pertaining to the domain of natural phenomena. According to him,
all bodies which are met with in nature, organic and inorganic alike, are
subject to the same laws. Life is a physical phenomenon, and all the
processes of life are due to mechanical causes, either physical or
chemical. He writes: "A leur source le physique et le moral ne sont sans
doute qu'une seule et meme chose. Il faut rechercher dans la consideration
de l'organisation les causes memes de la vie."
In the intellectual evolution of the human mind perhaps no advance has been
more important than that of Lamarck--the conquest of the domain of life by
human intelligence. In conformity with the true scientific method, he
founds his doctrine on the facts and phenomena of nature. "I confine
myself," he says, "within the bounds of a simple contemplation {161} of
nature." It was this observation of the gradual perfecting of living
organisms from the simplest to the most complicated that inspired Lamarck
with the idea of evolution and transformation. "How," he says, "can we help
searching for the cause of such wonderful results? Are we not compelled to
admit that nature has produced successively bodies endowed with life,
proceeding from the simplest to the most complex?"
The various products of nature have been divided into classes, genera, and
species, simply to facilitate their study. Modern research tends to show
that there is no definite line of demarcation even between the animal,
vegetable, and mineral kingdoms. All our classification is artificial, and
the passage from one division to another is gradual and insensible. Lamarck
expresses this idea very clearly: "We must remember that classes, orders,
and families, and all such nomenclature, are methods of our own invention.
In nature there are no such things as classes or orders or families, but
only individuals. As we become better acquainted with the productions of
nature, and as the number of specimens in our collections increases, we see
the intervals between the classes gradually fill up, and the lines of
separation become effaced."
Lamarck also raises his voice against the supposed immutability of species.
"Species have only a relative constancy, depending on the circumstances of
the individuals. The individuals of a given species perpetuate themselves
without variation only so long as there is no variation in the
circumstances which influence their existence. Numberless facts prove that
when an individual of a given species changes its locality, it is subjected
to a number of influences which little by little alter, not only the
consistency and proportions of its parts, but also its form, its faculty,
and even its organization; so that in time every part will participate in
the mutations which it has undergone."
Lamarck also clearly affirms the fact of spontaneous generation. "I hope to
prove," he says, "that nature possesses means and faculties for the
production of all the forms which we so much admire. Rudimentary animals
and plants have {162} been formed, and are still being formed to-day, by
spontaneous generation."
Lamarck himself gives a resume of his doctrine in the following six
propositions:--
1. "All the organized bodies of our globe are veritable productions of
Nature, which she has successively formed during the lapse of ages.
2. "Nature began, and still recommences day by day, with the production of
the simplest organic forms. These so-called spontaneous generations are her
direct work, the first sketches as it were of organization.
3. "The first sketches of an animal or a vegetable growth being begun under
favourable conditions, the faculties of commencing life and of organic
movement thus established have gradually developed little by little the
various parts and organs, which in process of time have become diversified.
4. "The faculty of growth is inherent in every part of an organized body;
it is the primary effect of life. This faculty of growth has given rise to
the various modes of multiplication and regeneration of the individual, and
by its means any progress which may have been acquired in the composition
and forms of the organism has been preserved.
5. "All living things which exist at the present day have been successively
formed by this means, aided by a long lapse of time, by favourable
conditions, and by the changes on the surface of the globe--in a word, by
the power which new situations and new habits have of modifying the organs
of a body which is endowed with life.
6. "Since all living things have undergone more or less change in their
organization, the species which have been thus insensibly and successively
produced can have but a relative constancy, and can be of no very great
antiquity."
The admirable work of Lamarck was absolutely neglected in France, where it
was treated as unworthy even of consideration. This neglect profoundly
afflicted Lamarck, who gradually sank a victim to the opposition of his
contemporaries. He left, however, one disciple, Etienne Jeoffroy St. {163}
Hilaire, but he too was soon reduced to silence under the weight of
authority of his adversaries.
[Illustration: FIG. 62.--Osmotic vegetation.]
Before the doctrine of evolution could live and take its proper place, it
had to be reborn in England--the country of liberty. This resuscitation was
due to Darwin, who added to it his illuminating doctrine of natural
selection. But apart from this and a perfecting of its various details,
Lamarck had already formulated the doctrine of evolution with perfect
precision. Lamarck's work was still-born, whereas that of Darwin lived and
grew to its full development. This was due, not to any imperfection or
insufficiency in Lamarck's work, but {164} to the milieu into which it was
born. It was the environment that stifled the offspring of Lamarck.
In 1868, Ernest Haeckel speaks of the genius of Lamarck in these words:
"The chief of the natural philosophers of France is Jean Lamarck, who takes
his place beside Goethe and Darwin in the history of evolution. To him
belongs the imperishable glory of being the first to formulate the theory
of descent, and of founding the philosophy of nature on the solid basis of
biology," and adds, "There is no country in Europe where Darwin's doctrine
has had so little influence as in France." Haeckel has but done tardy
justice in his discovery of and testimony to the genius of Lamarck.
The spirit of opposition does not seem to have much changed in France since
Lamarck's time. In 1907 the Academie des Sciences de Paris excluded from
its _Comptes Rendus_ the report of my researches on diffusion and osmosis,
because it raised the question of spontaneous generation.
The majority of scientists seem to consider that the question of
spontaneous generation was definitely settled once for all when Pasteur's
experiments showed that a sterilized liquid, kept in a closed tube,
remained sterile.
Without the idea of spontaneous generation and a physical theory of life,
the doctrine of evolution is a mutilated hypothesis without unity or
cohesion. On this point Lamarck speaks most clearly: "Although it is
customary when one speaks of the members of the animal or vegetable kingdom
to call them products of nature, it appears that no definite conception is
attached to the expression. Our preconceived notions hinder us from
recognising the fact that Nature herself possesses all the faculties and
all the means of producing living beings in any variety. She is able to
vary, very slowly but without cessation, all the different races and all
the different forms of life, and to maintain the general order which we see
in all her works."
The doctrine of Lamarck is frequently misinterpreted. We often hear it
expressed as "Function makes the organ," or even "Function creates the
organ." This is equivalent to saying, "Life makes the living being," which
is incomprehensible, {165} making of function a sort of immaterial and
independent entity which constructs a material organ in order to lodge
within it. No such idea is to be found in all the works of Lamarck. He
formulates his law in the following terms: "In every animal which is still
undergoing development, the frequent and sustained use of any one organ
increases its size and power, whereas the constant neglect of the use of
such organ weakens and deteriorates it, so that it finally disappears."
In his expression of this law Lamarck insists on the fact that organization
precedes function. He affirms only that function, _i.e._ action and
reaction, modifies the organ; or, in other words, that organisms are
modelled by the action of exterior forces acting upon them. It is in this
sense only that function may be said to make an organ, but this mode of
expression should be avoided, as it is apt to be misunderstood.
Astronomy teaches us that our globe was detached from the sun in an
incandescent state, and geology asserts that this earth has passed through
a period of long ages when its temperature was incompatible with the
existence of life. It was only with the cooling of the earth crust that it
was possible for living beings to make their appearance. Hence they must of
necessity have been produced spontaneously from terrestrial material under
the influences of chemical and physical forces. This opinion imposes itself
on all who reflect and judge freely. In the same way the doctrine of
evolution necessitates as a corollary the doctrine of spontaneous
generation. The doctrine of evolution should reconstitute every link in the
chain of beings from the simplest to the most complicated; it cannot afford
to leave out the most important of all, viz. the missing link between the
inorganic and the organic kingdoms. If there is a chain, it must be
continuous in all its parts, there can be no solution of continuity.
Evolutionists like Lamarck and Haeckel admit spontaneous generation, not as
the most probable, but as the only possible explanation of the phenomenon
of life.
Lamarck shows us the apparition of living things at a certain epoch of the
earth's evolution, and the gradual {166} development of more complicated
forms as the conditions changed on the surface of the globe. Darwin shows
how heredity and natural selection tend to accentuate the variations which
are favourable to existence. Haeckel demonstrates the parallelism between
ontogenesis and philogenesis--between the successive forms in the evolution
of the embryo and the successive forms of the individual in the evolution
of a race. These are great and admirable conquests of the human
intelligence, they have demonstrated the first appearance and the
progressive evolution of living beings; it now only remains for us to
explain them.
[Illustration: FIG. 63.--Marine forms of osmotic growth.]
The doctrine of evolution, while enforcing the fact of spontaneous
generation and progressive evolution, gives us no hint as to the physical
mechanism of such generation. It does not tell us by what forces, or
according to what laws, the simpler forms of life have been produced, or in
what manner differences of environment have acted in order to modify them.
The doctrine asserts the simultaneous variations in organic forms and in
the physical influences which produce them, but says {167} nothing as to
their mode of action. The Darwinian theory shows how acquired variations
are transmitted and accentuated by natural selection, but it says nothing
as to how these variations may be acquired. In the same way we are in
entire ignorance as to the physical mechanism of ontogenetic development,
the evolution of the embryo.
The morphogenic action of diffusion produces osmotic growths of extreme
variety. Most of these forms recall those of living things--shells, fungi,
corals, and algae. The analogy of function is quite as close as the
resemblance of form. The study of osmosis, however, is as yet in its
infancy, and osmotic productions vary with the physical conditions of
chemical constitution, temperature, concentration, and the like. The study
of the organizing action of osmosis on organic material has as yet been
hardly attempted.
Osmosis produces growths of great complexity, much more complicated indeed
than the more simple forms of living organisms. This marvellous complexity
of an osmotic growth may be compared with another fact, the ontogenetic
development of the ovum, a single cell which under favourable conditions of
environment may evolve into a most complicated organism. These
considerations lead to the belief that the beginning of life has not been
the production of a simple primitive form from which all others are
descended, but that a number of such primitive forms may have been
produced, forms which by a rapid physical development attained a high
degree of complexity. Osmotic morphogenesis shows us that the ordinary
physical forces have in fact a power of organization infinitely greater
than has been hitherto supposed by the boldest imagination.
When we consider the ignorance in which we still remain as to the phenomena
which pass before our very eyes, how can we expect to understand those
which occurred in past ages, when the physical and chemical conditions were
so immensely different from those which obtain in our own time? What do we
know even now of the physical and chemical phenomena which take place in
the unfathomed depths of the ocean, where for aught we know even at the
present time the same {168} process may be going on--the genesis of life,
and the emergence of living beings out of the inanimate mineral world?
"Even now," says Albert Gaudry, "polyps and oceanic animalculae are
building up vast coral reefs and rocks. The oxygen and hydrogen which
existed once was water, the oxygen and nitrogen which once made air, the
carbon, the phosphorus, the silica and the lime which once were solid rock,
now form the substance of living beings. The silica is deposited in the
skeleton of a sponge or a radiolaria, the shell of a foraminifera or the
carapace of a crustacean, or unites with phosphorus to form the bones of a
vertebrate. A very tumult of life has succeeded to the primitive silence of
inert matter. Life has invaded the earth, and we see on all sides the
inanimate mineral kingdom being changed into a living world."
The admission that life may have appeared on the earth under the influence
of natural forces and according to physical laws and conditions different
from those of the present era throws a vivid light on the study of
biogenesis, spontaneous generation, and evolution. The means of research
are now indicated, and we have only to study the documents already in our
possession in order to know the conditions which obtained when life first
appeared on the globe. We must endeavour to reproduce these conditions and
to study their effects.
Since all living beings are formed of the same elements as those of the
mineral world, the term "organic" as applied to combinations can only be
used in order to emphasize the complexity of their constitution. It was
formerly believed that these organic combinations were the result of life,
and could not be reproduced except by living organisms. To-day many of
these organic substances are produced in the laboratory from inorganic
materials. In the past history of the globe it is easy to imagine
conditions which would facilitate the synthesis of organic substances
without the interposition of life. At the temperature of the electric
furnace, which was that of the earth at an early period of its evolution,
chemical combinations are possible quite other than those obtaining under
the present conditions of temperature and pressure. At the higher
temperature of the early {169} geological era, silicides, carbides,
phosphides, and nitrides were formed in stable combinations instead of the
oxides, silicates, carbonates, phosphates, and nitrates of the present
time. These combinations existed on the earth at a time when the conditions
of temperature precluded the existence of water in a liquid state. As the
temperature cooled, and the water vapour became condensed, it entered into
chemical combination with the various rocks, producing organic compounds
like acetylene, which results from the action of water on calcium carbide.
H. Lenicque has developed a theory as to the formation of various rocks
under these conditions, which he communicated in 1903 to the French Society
of Civil Engineers.
The chemical evolution of the globe has undergone great changes as the
temperature gradually fell and the constitution of its crust altered. As
long as the temperature was higher than that at which water can exist, all
chemical reactions must have taken place between anhydric substances,
elements and salts in a state of fusion. These conditions are very
different from those of the present-day chemistry, which is the chemistry
of aqueous solutions. We may hope to be able to reproduce the earlier
conditions by the experimental study of anhydric substances in a state of
fusion.
At a later period, that of the primary and secondary rocks, there was a
uniform and constant temperature of about 40deg C. The atmosphere was
charged with water vapour, and all the conditions were present for the
production of storms and tempests. The atmosphere during long ages must
have been the seat of formidable and incessant electric discharges; these
discharges are the most powerful of all physical agents of chemical
synthesis, and will cause nitrogen to combine directly to form various
compounds--nitrates, cyanides, and ammonia. Carbonic acid would also be
present in abundance and would enter into combination with these
nitrogenous compounds. In this way we may imagine that compounds were
formed which by some process of physical synthesis subsequently gave rise
to vast quantities of albuminoid matter. At that time the seas and oceans
contained all those substances which have {170} since been fixed by the
metamorphism of the primitive rocks, or deposited in the sedimentary
strata. Most of the elements in our minerals were formerly in a state of
solution in these primeval seas, which contained carbonates, silicates, and
soluble phosphates in great abundance. As the crust gradually cooled, the
terrestrial atmosphere of necessity altered in composition, and the slow
evolution of the atmosphere no doubt also exercised an influence on the
development of living beings.
Palaeontology teaches us that the earliest living organism appeared in the
sea. The most ancient of living things, those of the primary ages, which
were of greater duration than all other ages put together, were all
aquatic. We find moreover that every living organism consists of liquids,
solutions of crystalloids and colloids separated by osmotic membranes; and
it is significant that the ocean, that vast laboratory of life, is also a
solution of crystalloids and colloids. It is evident, then, that we must
look to the study of solutions if we would hope to discover the nature and
origin of life.
Life is an ensemble of functions and of energy-transformations, an ensemble
which is conditioned by the form, the structure, and the composition of the
living being. Life, therefore, may be said to be conditioned by form,
_i.e._ the external, internal, and molecular forms of the living being.
All living things consist of closed cavities, which are limited by osmotic
membranes, and filled with solutions of crystalloids and colloids. The
study of synthetic biology is therefore the study of the physical forces
and conditions which can produce cavities surrounded by osmotic membranes,
which can associate and group such cavities, and differentiate and
specialize their functions. Such forces are precisely those which produce
osmotic growths, having the forms and exhibiting many of the functions of
living beings. Of all the theories as to the origin of life, that which
attributes it to osmosis and looks on the earliest living beings as
products of osmotic growths is the most probable and the most satisfying to
the reason.
[Illustration: FIG. 64.--Osmotic shells and corals.]
We have already seen that the seas of the primary and {171} secondary ages
presented in a high degree the particular conditions favourable for the
production of osmotic growths. During these long ages an exuberant growth
of osmotic vegetation must have been produced in these primeval seas. All
the substances which were capable of producing osmotic membranes by mutual
contact sprang into growth,--the soluble salts of calcium, carbonates,
phosphates, silicates, albuminoid matter, became organized as osmotic
productions,--were born, developed, evolved, dissociated, and died.
Millions of ephemeral forms must have succeeded one another in the natural
evolution of that age, when the living world was represented by matter thus
organized by osmosis.
The experimental study of osmotic morphogeny adds its weight of evidence in
the same direction. When we see under our own eyes the cells of calcium
become organized, develop and grow in close imitation of the forms of life,
we cannot doubt that such a transformation has often occurred in the past
history of our planet, and the conviction becomes irresistible {172} that
osmosis has played a predominant role in the history of our earth and its
inhabitants. It is a matter of astonishment that the scientist has taken no
notice of the active part which osmosis has played in the evolution of our
earth. On the effects of this most important physical phenomenon science
has hitherto remained entirely mute.
_Printed by_ MORRISON & GIBB LIMITED, _Edinburgh_
* * * * *
Corrections made to printed original.
Page 47. "into one where its osmotic pressure is low": 'into on' in
original.
Page 90. "the achromatin spindle in karyokinesis.": 'karineyoksis' in
original.
Page 120. "The researches of Famintzin": 'Famitzin' in original,
inconsistent with spelling 2 paragraphs earlier.
Page 141. "Similarly, if we suddenly dilute": 'Simiarly' in original.
Page 153. "which is accurately limited": 'acurately' in original.
Page 158. "this force is able to aggregate matter": 'this orce' in
original.