38 THE FIRST PRINCIPLES OF HEREDITY 



the heading of Karyokinesis. But here there are to be 

 noted two differences from the ordinary division. Firstly, 

 the two daughter- cells resulting from the division are of 



Fig. 27. — Maturation of Ovum. 



{From Weismann, " The Evolution Theory.") 



A, primitive ovum with four chromosomes ; B, mother-egg cell with 

 eight chromosomes ; C, first maturation-division ; D, formation 

 of first polar body (2) ; E, second maturation division and 

 division of first polar body into two {2 and 3) ; F, formation 

 of second polar body (4). 



very unequal size, the larger one remaining as the ovum 

 proper, while the smaller one forms the first polar body, 

 which thus comes to lie outside the ovum. The second 



