We do not feel quite sure that we seize Professor Kolliker"s meaning here, but he appears to suggest that the observation of the general order and harmony which pervade inorganic nature, would lead us to antic.i.p.ate a similar order and harmony in the organic world. And this is no doubt true, but it by no means follows that the particular order and harmony observed among them should be that which we see. Surely the stripes of dun horses, and the teeth of the _foetal_ _Balaena_, are not explained by the "existence of General laws of Nature." Mr. Darwin endeavours to explain the exact order of organic nature which exists; not the mere fact that there is some order.
And with regard to the existence of a natural system of minerals; the obvious reply is that there may be a natural cla.s.sification of any objects--of stones on a sea-beach, or of works of art; a natural cla.s.sification being simply an a.s.semblage of objects in groups, so as to express their most important and fundamental resemblances and differences.
No doubt Mr. Darwin believes that those resemblances and differences upon which our natural systems or cla.s.sifications of animals and plants are based, are resemblances and differences which have been produced genetically, but we can discover no reason for supposing that he denies the existence of natural cla.s.sifications of other kinds.
And, after all, is it quite so certain that a genetic relation may not underlie the cla.s.sification of minerals? The inorganic world has not always been what we see it. It has certainly had its metamorphoses, and, very probably, a long "Entwickelungsgeschichte" out of a nebular blastema. Who knows how far that amount of likeness among sets of minerals, in virtue of which they are now grouped into families and orders, may not be the expression of the common conditions to which that particular patch of nebulous fog, which may have been const.i.tuted by their atoms, and of which they may be, in the strictest sense, the descendants, was subjected?
It will be obvious from what has preceded, that we do not agree with Professor Kolliker in thinking the objections which he brings forward so weighty as to be fatal to Darwin"s view. But even if the case were otherwise, we should be unable to accept the "Theory of Heterogeneous Generation" which is offered as a subst.i.tute. That theory is thus stated:--
"The fundamental conception of this hypothesis is, that, under the influence of a general law of development, the germs of organisms produce others different from themselves. This might happen (1) by the fecundated ova pa.s.sing, in the course of their development, under particular circ.u.mstances, into higher forms; (2) by the primitive and later organisms producing other organisms without fecundation, out of germs or eggs (Parthenogenesis)."
In favour of this hypothesis, Professor Kolliker adduces the well-known facts of Agamogenesis, or "alternate generation"; the extreme dissimilarity of the males and females of many animals; and of the males, females, and neuters of those insects which live in colonies: and he defines its relations to the Darwinian theory as follows:--
"It is obvious that my hypothesis is apparently very similar to Darwin"s, inasmuch as I also consider that the various forms of animals have proceeded directly from one another. My hypothesis of the creation of organisms by heterogeneous generation, however, is distinguished very essentially from Darwin"s by the entire absence of the principle of useful variations and their natural selection: and my fundamental conception is this, that a great plan of development lies at the foundation of the origin of the whole organic world, impelling the simpler forms to more and more complex developments. How this law operates, what influences determine the development of the eggs and germs, and impel them to a.s.sume constantly new forms, I naturally cannot pretend to say; but I can at least adduce the great a.n.a.logy of the alternation of generations. If a _Bipinnaria_, a _Brachiolaria_, a _Pluteus_, is competent to produce the Echinoderm, which is so widely different from it; if a hydroid polype can produce the higher Medusa; if the vermiform Trematode "nurse" can develop within itself the very unlike _Cercaria_, it will not appear impossible that the egg, or ciliated embryo, of a sponge, for once, under special conditions, might become a hydroid polype, or the embryo of a Medusa, an Echinoderm."
It is obvious, from, these extracts, that Professor Kolliker"s hypothesis is based upon the supposed existence of a close a.n.a.logy between the phaenomena of Agamogenesis and the production of new species from pre-existing ones. But is the a.n.a.logy a real one? We think that it is not, and, by the hypothesis cannot be.
For what are the phaenomena of Agamogenesis, stated generally? An impregnated egg develops into a s.e.xless form, A; this gives rise, non-s.e.xually, to a second form or forms, B, more or less different from A.
B may multiply non-s.e.xually again; in the simpler cases, however, it does not, but, acquiring s.e.xual characters, produces impregnated eggs from whence A, once more, arises.
No case of Agamogenesis is known in which _when A differs widely from B_, it is itself capable of s.e.xual propagation. No case whatever is known in which the progeny of B, by s.e.xual generation, is other than a reproduction of A.
But if this be a true statement of the nature of the process of Agamogenesis, how can it enable us to comprehend the production of new species from already existing ones? Let us suppose Hyaenas to have preceded Dogs, and to have produced the latter in this way. Then the Hyaena will represent A, and the Dog, B. The first difficulty that presents itself is that the Hyaena must be non-s.e.xual, or the process will be wholly without a.n.a.logy in the world of Agamogenesis. But pa.s.sing over this difficulty, and supposing a male and female Dog to be produced at the same time from the Hyaena stock, the progeny of the pair, if the a.n.a.logy of the simpler kinds of Agamogenesis [Footnote: If, on the contrary, we follow the a.n.a.logy of the more complex forms of Agamogenesis, such as that exhibited by some _Trematoda_ and by the _Aphides_, the Hyaena must produce, non-s.e.xually, a brood of s.e.xless Dogs, from which other s.e.xless Dogs must proceed. At the end of a certain number of terms of the series, the Dogs would acquire s.e.xes and generate young; but these young would be, not Dogs, but Hyaenas. In fact, we have demonstrated, in Agamogenetic phaenomena, that inevitable recurrence to the original type, which is a.s.serted to be true of variations in general, by Mr. Darwin"s opponents; and which, if the a.s.sertion could be changed into a demonstration, would, in fact, be fatal to his hypothesis.] is to be followed, should be a litter, not of puppies, but of young Hyaenas. For the Agamogenetic series is always, as we have seen, A:B:A:B, &c.; whereas, for the production of a new species, the series must be A:B:B:B, &c. The production of new species, or genera, is the extreme permanent divergence from the primitive stock. All known Agamogenetic processes, on the other hand, end in a complete return to the primitive stock. How then is the production of new species to be rendered intelligible by the a.n.a.logy of Agamogenesis?
The other alternative put by Professor Kolliker--the pa.s.sage of fecundated ova in the course of their development into higher forms--would, if it occurred, be merely an extreme case of variation in the Darwinian sense, greater in degree than, but perfectly similar in kind to, that which occurred when the well-known Ancon Ram was developed from an ordinary Ewe"s ovum. Indeed we have always thought that Mr. Darwin has unnecessarily hampered himself by adhering so strictly to his favourite "Natura non facit saltum." We greatly suspect that she does make considerable jumps in the way of variation now and then, and that these saltations give rise to some of the gaps which appear to exist in the series of known forms.
Strongly and freely as we have ventured to disagree with Professor Kolliker, we have always done so with regret, and we trust without violating that respect which is due, not only to his scientific eminence and to the careful study which he has devoted to the subject, but to the perfect fairness of his argumentation, and the generous appreciation of the worth of Mr. Darwin"s labours which he always displays. It would be satisfactory to be able to say as much for M. Flourens.
But the Perpetual Secretary of the French Academy of Sciences deals with Mr. Darwin as the first Napoleon would have treated an "ideologue;" and while displaying a painful weakness of logic and shallowness of information, a.s.sumes a tone of authority, which always touches upon the ludicrous, and sometimes pa.s.ses the limits of good breeding.
For example (p. 56):--
"M. Darwin continue: "Aucune distinction absolue n"a ete et ne peut etre etablie entre les especes et les varietes." Je vous ai deja dit que vous vous trompiez; une distinction absolue separe les varietes d"avec les especes."
"_Je vous ai deja dit_; moi, M. le Secretaire perpetuel de l"Academie des Sciences: et vous
""Qui n"etes rien, Pas meme Academicien;"
what do you mean by a.s.serting the contrary?" Being devoid of the blessings of an Academy in England, we are unaccustomed to see our ablest men treated in this fashion, even by a "Perpetual Secretary."
Or again, considering that if there is any one quality of Mr. Darwin"s work to which friends and foes have alike borne witness, it is his candour and fairness in admitting and discussing objections, what is to be thought of M. Flourens" a.s.sertion, that
"M. Darwin ne cite que les auteurs qui partagent ses opinions." (P. 40.)
Once more (p. 65):--
"Enfin l"ouvrage de M. Darwin a paru. On ne peut qu"etre frappe du talent de l"auteur. Mais quo d"idees obscures, que d"idees fausses! Quel jargon metaphysique jete mal a propos dans l"histoire naturelle, qui tombe dans le galimatias des qu"elle sort des idees claires, des idees justes! Quel langage pretentieux et vide! Quelles personnifications pueriles et surannees! O lucidite! 0 solidite de l"esprit Francais, que devenez-vous?"
"Obscure ideas," "metaphysical jargon," "pretentious and empty language,"
"puerile and superannuated personifications." Mr. Darwin has many and hot opponents on this side of the Channel and in Germany, but we do not recollect to have found precisely these sins in the long catalogue of those hitherto laid to his charge. It is worth while, therefore, to examine into these discoveries effected solely by the aid of the "lucidity and solidity"
of the mind of M. Flourens.
According to M. Flourens, Mr. Darwin"s great error is that he has personified Nature (p. 10), and further that he has
"imagined a natural selection: he imagines afterwards that this power of selecting (_pouvoir d"elire_) which he gives to Nature is similar to the power of man. These two suppositions admitted, nothing stops him: he plays with Nature as he likes, and makes her do all he pleases." (P. 6.)
And this is the way M. Flourens extinguishes natural selection:
"Voyons donc encore une fois, ce qu"il peut y avoir de fonde dans ce qu"on nomme _election naturelle_.
"_L"election naturelle_ n"est sous un autre nom que la nature. Pour un etre organise, la nature n"est que l"organisation, ni plus ni moins.
"Il faudra donc aussi personnifier _l"organisation,_ et dire que _l"organisation_ choisit _l"organisation. L"election naturelle_ est cette _forme substantielle_ dont on jouait autrefois avec tant de facilite. Aristote disait que "Si l"art de batir etait dans le bois, cet art agirait comme la nature." A la place de _l"art de batir_ M. Darwin met _l"election naturelle,_ et c"est tout un: l"un n"est pas plus chimerique que l"autre." (P. 31.)
And this is really all that M. Flourens can make of Natural Selection. We have given the original, in fear lest a translation should be regarded as a travesty; but with the original before the reader, we may try to a.n.a.lyse the pa.s.sage. "For an organised being, Nature is only organisation, neither more nor less."
Organised beings then have absolutely no relation to inorganic nature: a plant does not depend on soil or sunshine, climate, depth in the ocean, height above it; the quant.i.ty of saline matters in water have no influence upon animal life; the subst.i.tution of carbonic acid for oxygen in our atmosphere would hurt n.o.body! That these are absurdities no one should know better than M. Flourens; but they are logical deductions from the a.s.sertion just quoted, and from the further statement that natural selection means only that "organisation chooses and selects organisation."
For if it be once admitted (what no sane man denies) that the chances of life of any given organism are increased by certain conditions (A) and diminished by their opposites (B), then it is mathematically certain that any change of conditions in the direction of (A) will exercise a selective influence in favour of that organism, tending to its increase and multiplication, while any change in the direction of (B) will exercise a selective influence against that organism, tending to its decrease and extinction.
Or, on the other hand, conditions remaining the same, let a given organism vary (and no one doubts that they do vary) in two directions: into one form (_a_) better fitted to cope with these conditions than the original stock, and a second (_b_) less well adapted to them. Then it is no less certain that the conditions in question must exercise a selective influence in favour of (_a_) and against (_b_), so that (_a_) will tend to predominance, and (_b_) to extirpation.
That M. Flourens should be unable to perceive the logical necessity of these simple arguments, which lie at the foundation of all Mr. Darwin"s reasoning; that he should confound an irrefragable deduction from the observed relations of organisms to the conditions which lie around them, with a metaphysical "forme substantielle," or a chimerical personification of the powers of Nature, would be incredible, were it not that other pa.s.sages of his work leave no room for doubt upon the subject.
"On imagine une _election naturelle_ que, pour plus de menagement, on me dit etre _inconsciente_, sans s"apercevoir que le contresens litteral est precis.e.m.e.nt la: _election inconsciente_." (P. 52.)
"J"ai deja dit ce qu"il faut penser de _l"election naturelle_. Ou _l"election naturelle_ n"est rien, ou c"est la nature: mais la nature douee _d"election_, mais la nature personnifiee: derniere erreur du dernier siecle: Le XIXe ne fait plus de personnifications." (P. 53.)
M. Flourens cannot imagine an unconscious selection--it is for him a contradiction in terms. Did M. Flourens ever visit one of the prettiest watering-places of "la belle France," the Baie d"Arcachon? If so, he will probably have pa.s.sed through the district of the Landes, and will have had an opportunity of observing the formation of "dunes" on a grand scale. What are these "dunes"? The winds and waves of the Bay of Biscay have not much consciousness, and yet they have with great care "selected," from among an infinity of ma.s.ses of silex of all shapes and sizes, which have been submitted to their action, all the grains of sand below a certain size, and have heaped them by themselves over a great area. This sand has been "unconsciously selected" from amidst the gravel in which it first lay with as much precision as if man had "consciously selected" it by the aid of a sieve. Physical Geology is full of such selections--of the picking out of the soft from the hard, of the soluble from the insoluble, of the fusible from the infusible, by natural agencies to which we are certainly not in the habit of ascribing consciousness.
But that which wind and sea are to a sandy beach, the sum of influences, which we term the "conditions of existence," is to living organisms. The weak are sifted out from the strong. A frosty night "selects" the hardy plants in a plantation from among the tender ones as effectually as if it were the wind, and they, the sand and pebbles, of our ill.u.s.tration; or, on the other hand, as if the intelligence of a gardener had been operative in cutting the weaker organisms down. The thistle, which has spread over the Pampas, to the destruction of native plants, has been more effectually "selected" by the unconscious operation of natural conditions than if a thousand agriculturists had spent their time in sowing it.
It is one of Mr. Darwin"s many great services to Biological science that he has demonstrated the significance of these facts. He has shown that given variation and given change of conditions the inevitable result is the exercise of such an influence upon organisms that one is helped and another is impeded; one tends to predominate, another to disappear; and thus the living world bears within itself, and is surrounded by, impulses towards incessant change.
But the truths just stated are as certain as any other physical laws, quite independently of the truth, or falsehood, of the hypothesis which Mr.
Darwin has based upon them; and that Mr. Flourens, missing the substance and grasping at a shadow, should be blind to the admirable exposition of them, which Mr. Darwin has given, and see nothing there but a "derniere erreur du dernier siecle"--a personification of Nature--leads us indeed to cry with him: "O lucidite! O solidite de l"esprit Francais, que devenez-vous?"
M. Flourens has, in fact, utterly failed to comprehend the first principles of the doctrine which he a.s.sails so rudely. His objections to details are of the old sort, so battered and hackneyed on this side of the Channel, that not even a Quarterly Reviewer could be induced to pick them up for the purpose of pelting Mr. Darwin over again. We have Cuvier and the mummies; M. Roulin and the domesticated animals of America; the difficulties presented by hybridism and by Palaeontology; Darwinism a _rifacciamento_ of De Maillet and Lamarck; Darwinism a system without a commencement, and its author bound to believe in M. Pouchet, &c. &c. How one knows it all by heart, and with what relief one reads at p. 65--
"Je laisse M. Darwin!"
But we cannot leave M. Flourens without calling our readers" attention to his wonderful tenth chapter, "De la Preexistence des Germes et de l"Epigenese," which opens thus:--
"Spontaneous generation is only a chimaera. This point established, two hypotheses remain: that of _pre-existence_ and that of _epigenesis_. The one of these hypotheses has as little foundation as the other." (p. 163.)
"The doctrine of _epigenesis_ is derived from Harvey: following by ocular inspection the development of the new being in the Windsor does, he saw each part appear successively, and taking the moment of _appearance_ for the moment of _formation_ he imagined _epigenesis_." (p. 165.)
On the contrary, says M. Flourens (p. 167),