1 88 Inheritance of Acquired Characters 



which there was equality and in which there were no 

 castes, the neutrals being nothing else than females 

 incompletely developed because of defective nutrition. 



It would not be correct to state that the question 

 has been finally decided through this debate. While 

 Weismann has not been able to prove conclusively that 

 these harmonious modifications of the neutrals have been 

 at least partially acquired after the development of castes 

 and when the sterility of the neutrals had already 

 appeared, neither has Spencer been able to demonstrate 

 that all these harmonious modifications had been already 

 acquired by the presocial ancestors. Nevertheless the 

 conception of Spencer that the neutrals are produced by 

 an arrest of development of the females has in our 

 opinion won a decisive victory over that of his opponent, 

 and has in reality taken from the last rampart of the 

 Weismannists all the strength which it had derived from 

 the conception that the neutrals were special formations, 

 which had acquired special characters by fortuitous vari- 

 ations and natural selection only. 



4. The fourth and last argument, that of the incon- 

 ceivability of the transmission of acquired characters, has 

 already been considered by Darwin in connection with 

 examples which he had himself communicated of the 

 inheritance of certain peculiarities, particularly of instincts 

 acquired by domestic animals. "Nothing in the whole 

 circuit of physiology," he stated in this connection, "is 

 more wonderful. How can the use or disuse of a partic- 

 ular limb or of the brain affect a small aggregate of 

 reproductive cells seated in a distant part of the body, 

 in such a manner that the being developed from these 

 cells inherits the characters of either one or both parents? 



