Vahie of Sexual Reproduclion. 155 



Gradually, as the life became more complex, 

 there were evolved creatures that budded off two 

 kinds of reproductive cells, one individual develop- 

 ing both kinds. Traces of this primitive hermaph- 

 roditism are found in all the higher life. 



Even in the highest mammals, including man, the 

 reproductive glands are at an early period neither 

 distinctly male nor female ; for a certain length of 

 time it seems to be uncertain whether the develop- 

 ing egg will produce male or female. In the form- 

 ing life the beginnings of the reproductive organs 

 of both sexes are present. Later, conditions of 

 nutrition seem to have decided in favor of one or 

 the other, and the male organs are gradually devel- 

 oped at the expense of the female, which linger as 

 the faintest traces, or the reverse is the case. 



So, as life advanced, the original hermaphrodite 

 developed to perfection but one set of reproductive 

 cells, and thus there was a division of labor effected. 



In the embryo, as the creature de\'eloping from 

 the egg is called, there reside the germs of botli 

 sexes, but in all the higher life the germs of only 

 one sex finally develop in an individual. 



Tremendous vitality is employed in the produc- 

 tion of reproductive cells, — so great that, if this 

 reproductive activity in the higher life be prevented 

 the whole organism un iergoes change. Instead of 

 being muscular and active, it becomes obese and 

 sluggish. The nutriment that otherwise would 

 have gone to the production of reproductive ele- 



