"1. Tendency of individuals to increase in number, while yet the actual number remains stationary. "2. A struggle for existence among those which compete for food and endeavour to escape death. "3. Survival of the fittest; meaning that those which die are least fitted to maintain their existence. "4. Hereditary transmission of a general likeness. "5. Individual differences among all. "6. Change of external conditions universal and unceasing. "7. Changes of organic forms to keep them in harmony with the changed conditions: and as the changes of condition are permanent, in the sense of not reverting back to identical previous conditions, the changes of organic forms must be in the same sense permanent, and thus originate species." The following passages from the "Origin of Species " may aid the comprehension of what the author admits to be a complex hypothesis: "There is a struggle for existence leading to the preservation of profitable deviations of structure and insects"-(p. 412.) "Natural selection acts solely through the preservation of advantageous variation, and it acts with extreme slowness, at long intervals of time, and only on a few inhabitants of the same region" (p. 108.) "It is not probable that variability is an inherent and necessary contingent under all circumstances; variability is governed by many unknown laws (p. 50). "We are profoundly ignorant of the cause of each slight variation or individual difference (p. 192). "Nature gives successive variations; man adds them up in certain directions useful to him" (p. 40). We italicise man because we are convinced that the grand fallacy in Darwin's theory lies just here, in the assumption that the selection and propagation of useful variations by man is in any way comparable to what takes place in nature. What is proved by all his works is this: that, so far as experience goes, no two created things are identical; that in many cases naturalists differ in their estimate of the value of the distinctions existing between individuals, so that what some call varieties others regard as species (a mighty question, which can only be decided by comparing great numbers of individuals of an undoubted species, and especially the progeny of a single pair); that by constant attention, by saving such as meet his wants and rejecting the rest, man has produced very strongly marked varieties, which continue "permanent" so long as this care is given, but which, the instant it is relaxed and a free crossing with other breeds is allowed, show that they are only varieties and not true species by reverting to the original stock. It may also be admitted that in nature a somewhat similar selection takes place, especially under the form of "sexual selection," but there is as yet no evidence whatever that natural species can be compared to the breeds of domesticated animals; and to ascribe to "selection" of any kind the power of originating species merely because it can preserve useful individual varieties, is as illogical as-if so homely a simile is allowable to suppose that the man who is able to manage his own house is, therefore, competent to "keep a hotel." Natural selection may be a true cause, but it is not shown to be a sufficient cause. any of It may here be noted that reversion is not mentioned in the statements of the theory of natural selection by either Darwin or Wallace. Yet the former treats of the subject at length, and even depends upon its agency, after the lapse of thousands of years, to account for the sudden reappearance of otherwise inexplicable structures; so that, if we give to reversion the weight which Darwin himself allows it when it favours his views, his arguments against its action (pages 28 and 160) do not remove what is really a very serious objection to the theory of natural selection as applied to the production of specific forms in nature. This whole subject is well presented by Mivart in the chapter on "Specific Stability;" and we have alluded to it here because it has always seemed to us to involve a fundamental fallacy which the author of "Natural Selection" is bound to remove. The object of the "Genesis of Species" is "to maintain the position that natural selection acts, and, indeed, must act; but that still, in order that we may be able to account for the production of known kinds of animals and plants, it requires to be supplemented by the action of some other natural law or laws, as yet undiscovered" (page 5). This is, we may remark, but one of the numerous evidences that, while the general theory of "derivation" has been steadily gaining adherents even from among its original opponents, yet "natural selection"-Darwinism "pure and simple"-has been, and is still, losing ground even with those who were inclined to adopt it. Huxley "adopts it only provisionally."* McCosh† admits that "it contains much truth, but not all, and overlooks more than it perceives." Lesley says, "All agree that it is true if kept within the regions of variety, but it is disputed whether it be true for actual specific differences." Wallace denies its sufficiency in the case of man, and Darwin himself has modified his views somewhat in this last edition of the "Origin of Species;" furthermore, he admits "the existence of difficulties so serious that he can hardly reflect on them without being staggered" (p. 167); and that "scarcely a single point is discussed on which facts cannot be adduced often apparently leading to conclusions opposite to mine" (p. 18). Indeed, with characteristic candour, he specifies certain ideas which if proved, would be fatal: "If it could be proved that any part of the structure of one species had been formed for the exclusive good of another species, it would annihilate my theory” (p. 196). We may, for example, yet learn the use which the "rattle" and the expanded hood have for the rattlesnake and the cobra, but Mivart is inclined to believe they are rather injurious, since they warn the prey (p. 50). Another such "fatal idea" is the doctrine that "many structures have been created for beauty in the eye of man or for mere variety" (p. 194). And here our author seems to contradict himself when, upon the same page, he admits that " many structures are now of no direct use to their possessors, and may never have been of any use to their progenitors"a subject which has been well discussed by the Duke of Argyll.§ The theory of natural selection implies that all changes are minute and gradual; and also that only useful structures are preserved and augmented. Prof. Mivart points out the difficulty of explaining the origin of the unsymmetrical form of the flounders, etc. (p. 37), of the limbs of animals which, in their earliest and minutest form, must have been mere buds or roughnesses, and thus rather impediments to the progress of our ancient aquatic progenitor (p. 39). Darwin further admits that "it is impossible to conceive by what steps the electric organs of fishes were produced (p. 184), also that the absence of imperfectly organized forms in the lowest strata of the earth's crust is inex "Man's Place in Nature," p. 128. Report of recent lectures. "Man's Origin and Destiny." § "Reign of Law," seventh edition, p. 230. plicable" (p. 292); and his explanation of the absence of the transitional forms which must have existed, according to his theory of "minute modifications in time," between such forms as the elephant, the giraffe, the galeopithecus, the bats, and the ordinary quadrupeds, is very unsatisfactory. His theory of rudimentary organs, also, is extremely imperfect. He accounts for all such from the disuse of previous perfect organs (p. 408); but he nowhere hints at the far more essential question as to how these original organs became perfect; for upon his own general hypothesis they must have been rudimentary in the beginning. With regret, and after the closest and most sincere examination of all his remarks upon this subject, we confess that we have rarely seen such an absolute lack of logical argument as is evinced in the section upon rudimentary and functionless structures. In fact, the immense amount of evidence which he has collected does not seem to us to bear upon the main point, the origin of species, at all, but only upon the preservation of favourable individual variations, We have not space for further presentation of our own difficulties or those which others have urged against the theory of natural selection, and will simply quote the general grounds upon which Prof. Mivart has been led, with no prejudice against it, to regard that theory as playing only a subordinate part in the production of new species (p. 21): "Natural selection is incompetent to account for the incipient stages of useful structures. It does not harmonize with the coexistence of closely similar structures of diverse origin." "Certain fossil transitional forms are absent which might have been expected to be present; and some facts of geographical distribution supplement other difficulties. There are many remarkable phenomena in organic forms upon which natural selection throws no light whatever." "Still other objections may be brought against the hypothesis of 'pangenesis' which, professing as it does to explain great difficulties, seems to do so by presenting others not less greatalmost to be the explanation of obscurum per obscurius." These difficulties, which are set forth with equal cogency and fairness in the earlier chapters of the "Genesis of Species," have Propounded at the close of the work upon Variation under Domestication." led its author to a view which he alludes to throughout his work, but presents in detail in the chapter entitled "Specific Genesis." "According to this view, an internal law presides over the actions of every part of every individual, and of every organism as a unit, and of the entire organic world as a whole. It is believed that this conception of an internal innate force will ever remain necessary, however much its subordinate processes and actions may become explicable. That by such a force, from time to time, new species are manifested by ordinary generation, these new forms not being monstrosities, but consistent wholes. That these 'jumps' are considerable in comparison with the minute variations of 'natural selection'-are, in fact, sensible steps, such as discriminate species from species. That the latent tendency which exists to these sudden evolutions is determined to action by the stimulus of external condition." The part assigned to natural selection is stated as follows: "It rigorously destroys monstrosities, favours and develops useful variations, and removes the antecedent species rapidly when the new one evolved is more in harmony with surrounding conditions." Professor Mivart has so frankly admitted the essential coincidence of the above view with the one expressed by Professor Owen in 1868, that we do not hesitate to call his attention to the similar views previously advanced by Professor Parsons, of Harvard University, and by the anonymous author of "Vestiges of Creation;" believing that his own conclusions were reached in entire independence of all of them, as is said of Professor Owen's. The author of the "Vestiges" expresses himself as follows: † "My idea is, that the simplest and most primitive type, under a law to which that of like-production is subordinate, gave birth to the type next above it, that this again produced the next higher, and so on to the very highest, the stages of advance being in all cases very small, namely, from one species only to another. Yet in another point of view, the phenomena are wonders of the highest kind, in so far as they are direct effects of an Almighty will, which had provided beforehand that everything should be very good." * 170. "Comp. Anat. and Phys. of Vertebrates," vol. iii. p. 808. VOL. VI. B No. 1. |