INADEQUACY OP NATURAL SELECTION, ETC. 677 



at issue, had that issue then been raised, and I certainly do not 

 see it now. Full reproduction of Professor Weismann's explana- 

 tion is impracticable, for it occupies several pages, but here are 

 the essential sentences from it : — 



" The great significance of intra-sclection appears to me not to depend on 

 its producing structures that are directly transmissible, — it cannot do that, — 

 but rather consists in its causing a development of the germ-structure, 

 acquired by the selection of individuals, which will be suitable to varying 

 conditions. . . . We may therefore say that intra-selection effects the 

 adaptation of the individual to its chance developmental conditions, — the 

 suiting of the hereditary primary constituents to fresh circumstances" 

 (p, 16). . . . "But as the primary variations in the phyletic metamor- 

 phosis occurred little by little, the secondary adaptations would probably as 

 a rule be able to keep pace with them. Time would thus be gained till, in 

 the course of generations, by constant selection of those germs the primary 

 constituents of which are best suited to one another, the greatest possible 

 degree of harmony may be reached, and consequently a definitive metamor- 

 phosis of the species involving all the parts of the individual may occur " 

 (p. 19). 



The connecting sentences, along with those which precede 

 and succeed, would not, if quoted, give to the reader clearer 

 conceptions than these by themselves give. But when dis- 

 entangled from Professor Weismann's involved statements, the 

 essential issues are, I think, clear enough. In the case of the 

 stag, that daily working together of the numerous nerves, muscles, 

 and bones concerned, by which they are adjusted to the carrying 

 and using of somewhat heavier horns, produces on them effects 

 which, as I hold, are inheritable, but which, as Professor Weis- 

 mann holds, are not inheritable. If they are not inheritable, 

 what must happen ? A fawn of the next generation is born with 

 no such adjustment of nerves, muscles and bones as had been 

 produced .by greater exercise in the parent, and with no tendency 

 to such adjustment. Consequently if, in successive generations, 

 the horns go on enlarging, all these nerves, muscles, and bones, 

 remaining of the original sizes, become utterly inadequate. The 

 result is loss of life : the process of adaptation fails. " No," says 

 Professor Weismann, " we must conclude that the germ-plasm 

 has varied in the needful manner." How so ? The process of 

 " intra-individual selection," as he calls it, can have had no effect, 

 since the cells of the soma cannot influence the reproductive cells. 

 In what way, then, has the germ-plasm gained the characters 

 required for producing simultaneously all these modified co- 

 operative parts. Well, Professor Weismann tells us merely that 

 we must suppose that the germ-plasm acquires a certain sensitive- 

 ness such as gives it a proclivity to development in the requisite 

 ways. How is such proclivity obtainable ? Only by having a 

 multitude of its " determinants " simultaneously changed in fit 

 modes. Emphasizing the fact that even a small failure in any 



