C. Lloyd Morgan 343 



mitted, but a cell mass, that from the germ onward so reacts 

 to tension and pressure that the spongy structure necessarily 

 results.' In other words, it is not the more or less definite 

 congenital adaptation that is handed on through heredity, but 

 an innate plasticity which renders possible adaptive modifi- 

 cation in the individual. 



" This innate plasticity is undoubtedly of great advantage in 

 race progress. The adapted organism will escape elimination 

 in the life struggle ; and it matters not whether the adaptation 

 be reached through individual modification of the bodily tissues 

 or through racial variation of germinal origin. So long as the 

 adaptation is there, — no matter how it is originated, — that is 

 sufficient to secure survival. Professor Weismann applies this 

 conception to one of those difficulties which have been urged 

 by critics of natural selection. 'Let us take,' he says,^ 'the 

 well-known instance of the gradual increase in development of 

 the deer's antlers, in consequence of which the head in the 

 course of generations has become more and more heavily 

 loaded. The question has been asked as to how it is possible 

 for the parts of the body which have to support and move this 

 weight to vary simultaneously and harmoniously if there is no 

 such thing as the transmission of the effects of use or disuse, 

 and if the changes have resulted from processes of selection 

 only. This is the question put by Herbert Spencer as to 

 '•^ coadaptation,^' and the answer is to be found in connection 

 with the process of intra-selection. It is by no means necessary 

 that all the parts concerned — skull, muscles, and ligaments of 

 the neck, cervical vertebrae, bones of the four limbs, etc. — 

 should simultaneously adapt themselves by variation of the germ 

 to the increase of the size of the antlers ; for in each separate 

 individual the necessary adaptation will be temporarily accom- 

 plished by intra-selection,' that is, by individual modification due 

 to the innate plasticity of the parts concerned. ' The improve- 

 ment of the parts in question,' Professor Weismann urges, 

 ' when so acquired, will certainly not be transmitted, but yet 

 the primary variation is not lost. Thus when an advantageous 

 1 Romanes Lecture, pp. i8, 19. 



