CHAPTER V 



REDUCTION 



IN the study of reproduction a process has 

 been observed to which the name " reduction " 

 is given. As a necessary step to the reception 

 of the male germ, the egg before fertilization 

 throws off two small parts called polar bodies. 

 The first of these, according to Professor 

 Weismann, represents the separation from the 

 nucleus of the ovogenetic nuclear substance, 

 and the second is a real division of the cell, 

 by which one-half of the essential elements of 

 the nucleus, called chromosomes, are ejected. 

 The egg is thus made ready for the recep- 

 tion of the sperm, and, through the union, the 

 nucleus is restored to its original number of 

 chromosomes and made capable of independ- 

 ent life. 



The formation of polar bodies is evidently 

 a process of cell division observed under con- 

 ditions incident to reproduction. The question 



E 49 



