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Show 6 DARWINISM CIIAP. nature and ongm of species. They render it clear that, notwithstanding the vast knowledge and ingenious reasoning of Lamarck, and the more general exposition of the subject by the author of the Vestiges of Cr-eation, the first step had not been taken towards a satisfactory explanation of the derivation of any one species from any other. Such eminent naturalists as Geoffroy Saint Hilaire, Dean Herbert, Professor Grant, Von Buch, and some others, had expres ·eel their belief that species arose as simple varieties, and that the species of each genus were all descended from a common ancestor; but none of them gave a clue as to the law or the method hy which the change had been effected. This was still "the great mystery." As to the further question-how far this common descent could be carried ; whether distinct families, such as crows and thrushes, could possibly have descended from each other; or, whether all birds, including such widely eli tinct types as wrens, eagles, ostriches, and ducks, could all be the modified descendants of a common ancestor; or, still further, whether mammalia, birds, reptiles, and fishes, could nJl have had a common origin ;-these questions had hardly come up for discussion at all, for it was felt that, while the very fir. t step along the road of "transmutation of species " (n. it was then called) had not been made, it was quite u eless to speculate as to how far it might be possible to travel in the same direction, or where the road would ultimately lead to. The Pr-oblern before Darwin. It is clear, then, that what was understood by tho "origin " or the " transmutation" of species before Darwin's work appeared, was the comparatively simple question whether the allied species of each genus had or had not been derived from one an~ther and, remotely, from some common ancestor, by the ordmary method of reproduction and by means of laws and conditions still in action and capable of beino- thorouo·hly . . b b mvestigated. I! a~y naturalist had been asked at that day whether, sp.pposmg It to be clearly shown that all the different species of each genus had been derived from some one ancestral spec~es, and that a full and complete explanation were to be given of how each minute difference in form colour, or structure might have originated, and bow tb~ 7 se:'eral pecnliarities of habit and of geogra.phical distribution m1ght have been brought about-whether, if thi w •rc done, the "origin of species" would he di ·covered, the great mystery solved, be would undoubtedly have replied in the affirmative. He would probably have added that he never expected any uch marvellous discovery to be made in his lifetime. But so much a· this assuredly Mr. Darwin has done, not only in the opinion of hi eli ciplc. and admirer., but by the admissions of those who doubt the completeness of his explanations. For almost all their objections and difficulties apply to those larger differences which cparat • genera, families, and orders from each other, not to those ·which se1~ara.te one specie from the specie to which it i mo. t nearly alhecl, and from the remaining specie. of the same genu . They adduce such difficultie as the fir. t development of the eye, or of the milk-producing glands of the mammalia; the wonderful instincts of bees and of ants; the complex arran,rement. for the fertili ation of orchids, and numerous othc~ points of structure or habit, as not being satisfactorily exphincd. But it is evident that the e peculiarities had their origin at a very remote period of the earth's history, and no theory, however complete, can do more than afford c.t probable conjecture as to how they were produced. Our ignorance of the . tate of the earth's surface ancl of the conditions of life at tho:e r 'mote periods is very (rrc<Lt; thousands of animals and plants must hnve cxi tecl of which we have no record; while we are u ually without any information as to the lmbi ts and rrencral 1ifc-h~ tory even of tho. c of which we po:l::ics. some frag;cntary remams ; . o that the truest and most complete theory would not enable us to solve all the difficult problems which the whole course of the development of life upon onr globe present. to us. \Vha.t we ma.y expect a trnc theory to do i. to enahlc us to compr hen<l and follow ont in Rome detail tho e changes in the form, strncture, and rclationl::i of anim1tl: and plant: which are cifcctccl in short periods of time, u 'ologically pcc.Lking, and which arc now going on aromul us. \V c may expect it, to explain satisfactorily most of the lesser and superficial differences whi<;h distingui h one pc<;ics from another. \V c may expect it to throw light on the mutual rcla tions of the |