Chap. 18 



REPRODUCTION 



CASTRATES 



345 



NORMAL 

 COCK 



CASTRATE 

 CCXK 



NORMAL 

 MEN 



y 



CASTRATE 

 HEN 



?¥ 



NORMAL 

 COW 



fT 



CASTRATE 

 COW 



ft 



NORMAL 

 MAN 



EUNUCHOID 

 GIANT 



Note difference in length of A, A' and 

 B, B\ In normal A=B, in eunuchoid 

 giant B' ii greater thon A'. 



Fig. 18.9. Effects of castration on the shape of the body. These do not occur 

 when sterilization is done by cutting or ligating sperm ducts without removing the 

 testes. (Courtesy, Gregory: A, B, C of the Endocrines. Baltimore, Williams & Wil- 

 kins Co., 1935.) 



for certain changes in the reproductive tract. As the egg matures, it hangs out 

 into the cavity of the follicle which is swollen with fluid so that it protrudes 

 like a minute volcano on the surface of the ovary (Figs. 18.11 and 18.12). 

 At length, the wall of the follicle breaks and egg and fluid are set free; this is 

 ovulation. Human ovulation may occur irregularly in the right or left ovary; 

 ordinarily but one egg is freed per monthly cycle, but there may be two and 

 rarely even more. As an egg matures, the number of its chromosomes is re- 

 duced to half that of the parent's body. In the human egg, the number is cut 

 from 48 to 24. This involves two divisions (Chap. 3). The first one occurs 

 before ovulation. 



