CHAPTER I 

 REPRODUCTION 



1. REPRODUCTION IN ANIMALS. 



WE have seen in the previous chapter that the male 

 and female germ cells are brought together in the 

 act of mating. It has also been pointed out that in 

 individuals of bisexual species (those having both 



FIG. 33. OVUM, SURROUNDED BY SPERM CELLS. (After Schenck.) 



Ei, Ovum ; Sp, sperm cells. 

 (Prom Weismann, " The Evolution Theory.") 



males and females) the male and female germs must 

 combine in order to produce the new being. This 

 mingling of the two germs is called fertilization 

 in the higher animals; also known as conception. 

 As a rule it is the small active sperm that penetrates 



90 



