MATURATION 



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nucleus of the large cell divides again without an intervening 

 resting stage, and a second polar body is formed. As a result 

 of these two divisions there are now one large cell — the ripe 



Fig. 184. — Diagram illustrating the reduction of the chromosomes during the 

 maturation of the ovum. (McMurrich.) 0, Ovum; oc^, oocyte of the first 

 generation; oc^, oocyte of the second generation; p, polar globule. The number 

 of the chromosomes is supposed to be 8( = 2x) in the zygote, and 4( = x) in the 

 gametes. 



egg — and two small ones. The nucleus of the egg cell has two 

 chromosomes, and so has the second polar body. If the first 

 polar body were to divide in the same way, there would have 

 been three polar bodies, each with two chromosomes. This 



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