species being distinct) is by reversion, owing to a supposed ancestral cross. But he candidly admits, "I have heard of no other such case in the animal or vegetable kingdom. On the supposition of its being only a variety, he observes, "The case is the most remarkable ever recorded of the abrupt appearance of a new form, which so closely resembles a true species, that it has deceived one of the most experienced of living ornithologists." 16 As to plants, M. C. Naudin 1 has given the following instances of the sudden origination of apparently permanent forms: "The first case mentioned is that of a poppy, which took on a remarkable variation in its fruit-a crown of secondary capsules being added to the normal central capsule. A field of such poppies was grown, and M. Göppert, with seed from this field, obtained still this monstrous form in great quantity. Deformities of ferns are sometimes sought after by fern-growers. They are now always obtained by taking spores from the abnormal parts of the monstrous fern; from which spores ferns presenting the same peculiarities invariably grow. The most remark able case is that observed by Dr. Godron, of Nancy. In 1861 that botanist observed, among a sowing of Datura tatula, the fruits of which are very spinous, a single individual of which the capsule was perfectly smooth. The seeds taken from this plant all furnished plants having the character of this individual. The fifth and sixth generations are now growing without exhibiting the least tendency to revert to the spinous form. More remarkable still, when crossed with the normal Datura tatula, hybrids were produced, which, in the second generation, reverted to the original types, as true hybrids do." There are, then, abundant instances to prove that considerable modifications may suddenly develop themselves, 16 Extracted by J. J. Murphy, vol. i., p. 197, from the Quarterly Journal of Science, of October, 1867, p. 527. either due to external conditions or to obscure internal causes in the organisms which exhibit them. Moreover, these modifications, from whatever cause arising, are capable of reproduction-the modified individuals "breeding true." The question is, whether new species have been developed by non-fortuitous variations which are insignificant and minute, or whether such variations have been comparatively sudden, and of appreciable size and importance? Either hypothesis will suit the views here maintained equally well (those views being opposed only to fortuitous, indefinite variations), but the latter is the more remote from the Darwinian conception, and yet has much to be said in its favor. 99 17 Prof. Owen considers, with regard to specific origination, that natural history "teaches that the change would be sudden and considerable: it opposes the idea that species are transmitted by minute and slow degrees. "An innate tendency to deviate from parental type, operating through periods of adequate duration," being "the most probable nature, or way of operation of the secondary law, whereby species have been derived one from the other." 18 Now, considering the number of instances adduced of sudden modifications in domestic animals, it is somewhat startling to meet with Mr Darwin's dogmatic assertion that it is "a false belief" that natural species have often originated in the same abrupt manner. The belief may be false, but it is difficult to see how its falsehood can be positively asserted. It is demonstrated by Mr. Darwin's careful weighings and measurements that, though little-used parts in domestic animals get reduced in weight and somewhat in size, 17 "Anatomy of Vertebrates," vol. iii., p. 795. 18 Ibid., p. 807. yet that they show no inclination to become truly "rudimentary structures." Accordingly he asserts 19 that such rudimentary parts are formed "suddenly by arrest of development" in domesticated animals, but in wild animals slowly. The latter assertion, however, is a mere assertion; necessary, perhaps, for the theory of "Natural Selection," but as yet unproved by facts. 20 But why should not these changes take place suddenly in a state of nature? As Mr. Murphy says,' As Mr. Murphy says, "It may be true that we have no evidence of the origin of wild species in this way. But this is not a case in which negative evidence proves any thing. We have never witnessed the origin of a wild species by any process whatever; and if a species were to come suddenly into being in the wild state, as the Ancon Sheep did under domestication, how could you ascertain the fact? If the first of a newly-begotten species were found, the fact of its discovery would tell nothing about its origin. Naturalists would register it as a very rare species, having been only once met with, but they would have no means of knowing whether it were the first or the last of its race." To this Mr. Wallace has replied (in his review of Mr. Murphy's work in Nature"), by objecting that sudden changes could very rarely be useful, because each kind of animal is a nicely-balanced and adjusted whole, any one sudden modification of which would in most cases be hurtful unless accompanied by other simultaneous and harmonious modifications. If, however, it is not unlikely that there is an innate tendency to deviate at certain times, and under certain conditions, it is no more unlikely that that innate tendency should be a harmonious one, calculated to simultaneously adjust the various parts of the organism to their 19 “ Animals and Plants under Domestication," vol. ii., p. 318. 21 See December 2, 1869, vol. i., p. 132. new relations. The objection as to the sudden abortion of rudimentary organs may be similarly met. Prof. Huxley seems now disposed to accept the, at least occasional, intervention of sudden and considerable variations. In his review of Prof. Kölliker's 22 criticisms, he 线 MUCH ENLARGED HORIZONTAL SECTION OF THE TOOTII OF A LABYRINTHIODON. himself says, 23"We greatly suspect that she" (i. e., Nature) "does make considerable jumps in the way of variation now and then, and that these saltations give rise to 22 Über die Darwin'sche Schöpfungstheorie:" ein Vortrag, von Kölliker; Leipzig, 1864. 23 See "Lay Sermons," p. 342. some of the gaps which appear to exist in the series of known forms.' In addition to the instances brought forward in the second chapter against the minute action of Natural Selection, may be mentioned such structures as the wonderfully folded teeth of the labyrinthodonts. The marvellously complex structure of these organs is not merely unaccountable as due to “Natural Selection," but its production by insignificant increments of complexity is hardly less difficult to comprehend. Similarly the aborted index of the Potto (Perodicticus) is a structure not likely to have been induced by minute changes; while, as to "Natural Selection," the reduction of the fore-finger to a mere rudiment is inexplicable indeed! "How this mutilation can have aided in the strug HAND OF THE POTTO (PERODICTIOUS), FROM LIFE. gle for life, we must confess, baffles our conjectures on the subject; for that any very appreciable gain to the individual can have resulted from the slightly-lessened degree of required nourishment thence resulting (i. e., from the suppression), seems to us to be an almost absurd proposition. 24 Again, to anticipate somewhat, the great group of whales (Cetacea) was fully developed at the deposition of the Eocene strata. On the other hand, we may pretty safely conclude that these animals were absent as late as 24 "Anatomy of the Lemuroidea," by James Murie, M. D., and St. George Mivart. Trans. Zool. Soc., March, 1866, p. 91 |