DR. ASA GRAY ON DARWINISM. 



191 



istry, we find the scientific world, with but few 

 individual exceptions, quite content to accept 

 the nebular hypothesis framed by Laplace, and 

 to believe that the matter of the solar system 

 existed originally in the form of a vast diffused 

 revolving mass, which, gradually cooling and 

 contracting, threw off, in obedience to me- 

 chanical laws, successive rings, from which sub- 

 sequently, by the same laws, were produced the 

 several planets, satellites, and other bodies ol the 

 system. Such a theory is indeed justly regarded 

 as the complement and corollary of the Newtonian 

 doctrine, which proves that certain forces acting 

 upon matter in certain directions produce planet- 

 ary orbits of the exact measure and form in 

 which observation shows them to exist. The 

 merest tyro in science regards light, heat, elec- 

 tricity, magnetism, chemical affinity, and me- 

 chanical power, as varieties or derivative and 

 convertible forms of one force, instead of believ- 

 ing them independent species ; and chemists 

 have lately hinted their anticipation that some 

 or all of the supposed elementary bodies will be 

 found to be themselves compound and derivative, 

 while here and there appears a man bold enough 

 to record his conviction that all these substances 

 will be at last reducible to one, precisely as 

 Haeckel believes that he can trace the genesis of 

 man and of all species to a single simple element 

 — the protoplasmic cytode. 



The true reason, no doubt, why the doctrine 

 of evolution, as applied to animal existences, 

 has failed to become popular, is that it involves 

 the origin of the human race, and affects, as 

 some suppose, the dignity of man's position as the 

 creature distinctively soul-endowed. The scien- 

 tific difficulty of this knotty point — which is the 

 logical outcome and conclusion of the theory of 

 development — lies in the explanation of Mr. Dar- 

 win's term, " differentiation" Mr. Darwin says • 

 "In each member of the vertebrate series, the 

 nerve-cells of the brain are the direct offshoots 

 of those possessed by the common progenitor of 

 the whole group. It thus becomes intelligible 

 that the brain and mental faculties should be 

 capable, under similar conditions, of nearly the 

 same course of development, and consequently 

 of performing nearly the same functions." Now 

 the brain-cells of man, as he is at present consti- 

 tuted, have no known analogy or representative 

 among the lower animals. In order to fill up the 

 gap existing between the highest extant group 

 of the simias and man, Haeckel has found it neces- 

 sary to invent an intermediate extinct species, to 

 which he gives the name of "speechless ape- 



men," assigning to them the glacial, post-glacial, 

 and historic periods, summed up in the Anthro- 

 polithic age. The fact is, that there exists a 

 notable hiatus in the ascending scale, for which 

 hitherto evolutionists have failed to account sat- 

 isfactorily. It is easy to silence, or at least to 

 puzzle, lay objectors by the use of long scientific 

 terms and phrases, but among physiologists 

 much doubt and uncertainty exist with regard 

 to the application of the word " differentiation," 

 in the sense in which evolutionists are at present 

 fond of employing it. Cells may or may not be 

 admitted to be spontaneously generated, but it 

 can at least be shown that each kind of cell, once 

 in existence, has its own special endowments, 

 and its own special method of development. 

 One kind of cell has never been known to de- 

 velop into or to perform the functions of another 

 kind. Nerve-cells cannot, by means of any con- 

 ceivable process, become cells of another sort 

 of tissue even in the same structure ; nor will 

 the cells composing the olfactory nerve ex- 

 change office with those which constitute the op- 

 tic, the auditive, or any other of its coadjutors, 

 begotten of the same substance and on the same 

 territory. With this truth present to the mind, 

 it is difficult to understand how the brain-cells 

 of the ape can ever have so altered in character 

 and in destiny as to have " differentiated " them- 

 selves into human brain-cells. Mr. Herbert Spen- 

 cer might, perhaps, wish to dispose of this diffi- 

 culty, as he seeks to do with its analogue, upon 

 the very threshold of the evolution theory, by as- 

 suming that the distance apparently separating 

 inorganic from organic substances may be bridged 

 over by an hypothesis relegating the dissimilarity 

 of mode and function to a mere difference of 

 molecular adjustment and arrangement. But if 

 philosophy can theoretically solve the problem of 

 life with so much ease, how comes it that chem- 

 istry remains still practically unable to demon- 

 strate this assumed convertibility of matter? De- 

 spite all the confidence hypothetically entertained 

 on the subject of the identity of inorganic and or- 

 ganic compounds, no scientific man has yet been 

 able to construct a single particle of organizable 

 protein, much less a vitally-endowed cell. It wilJ 

 be evident, on a little reflection, that the most 

 important inference deducible from the theory of 

 development, as expounded by the materialistic 

 school, is one which refers all modes of being, 

 organic and inorganic, to the operation of mere 

 mechanical power. But if this be a true conclu- 

 sion, it is hard to comprehend how that power — 

 unconscious and characterless — should be capa- 



