EFFECTS OF SEXUAL REPRODUCTION. 255 



and that part which accumulates after the age of puberty tends to 

 be inherited by sex. In the human species we find the brain of man 

 larger and stronger than that of woman, and we can find the ex- 

 planation in the fact that men are mentally more active than women, 

 and that fathers average three or four years older than mothers. 

 From the further fact that the procreative powers of men extend 

 to a later age than they do with women, we may conclude that by 

 no possibility can the mental powers of women overtake those of 

 men. Certain individual women will of course exceed certain indi- 

 vidual men, but there will always be certain men who will exceed 

 any possible women. 



TRANSFERENCE OF SEXUALLY DEVELOPED CHARACTERS TO THE OP- 

 POSITE SEX. 



While characters developed in the adult by functional activity 

 are transmitted principally, if not exclusively, to offspring of the 

 same sex, there is a process by which such sexually developed char- 

 acters are gradually transferred to individuals of the opposite sex. 

 Thus, the combined result of great functional activity and late re- 

 production produce an individual who starts his development with 

 a great initial velocity and consequently reaches, before puberty, a 

 greater development than his father reached at that period of his 

 life. Whatever is thus developed in the new individual before 

 puberty by reason of greater initial velocity, is transmitted alike to 

 both sexes of the next generation, and whatever is developed after 

 puberty is transmitted to the same sex. If this new individual of 

 the second generation should also accumulate the result of much 

 use before reproducing, then the descendant in the third genera- 

 tion would develop with still greater rapidity and consequently 

 would transmit a greater amount to the opposite sex in the fourth 

 generation. 



