CHAPTER I 



THE PROBLEM DEFINED 



What is sex ? Asexual and mixed reproduction ; Origin of 

 sexual reproduction ; Advantage of sex in chance of 

 survival ; Germ and body cells ; Limitations of biology 

 in social problems ; Sex always present in higher ani- 

 mals ; Sex in mammals ; The sex problem in the human 

 species ; Application of laboratory method. 



Sex, like all complicated phenomena, defies 

 being crowded into a simple definition. In an 

 animal or plant individual it is expressed by 

 and linked with the ability to produce egg- or 

 sperm-cells (ova or spermatozoa). Sexual re- 

 production is simply the chain of events 

 following the union of the egg and sperm to 

 produce a new individual. Looked at from 

 another angle, it is that sort of reproduction 

 which requires two differentiated individuals : 

 the male, which produces spermatoza, and the 

 female, which produces ova. In the case of 

 very simple forms, it would be simply the union 

 or conjugation of a male and a female individual 

 and the reproductive process involved. Where 

 there is no differentiation into male and female 

 there is no sex. 



