THE FEMALE 



69 





The maturation divisions in the female (Axolotl). (1) First polar spindle with 

 heterotypic chromosomes. (2) Extrusion of first polar body. (3) Appearance of 

 second polar spindle. Longitudinal division of chromosomes in egg and in first 

 polar body. (4) Second polar spindle radial. Homoeotypic chromosomes on 

 equator (metaphase). (5) Polar view of the same. (6) Anaphase. (7) Extrusion 

 of second polar body. (8) Second polar body with resting nucleus. (9) Female 

 pronucleus in resting condition, closely surrounded by yolk granules. (Courtesy, 

 Jenkinson: "Vertebrate Embryology," Oxford, The Clarendon Press.) 



[Continued from opposite page.) 

 the presence of the follicle and cyst wall, and the predetermined area of ultimate 

 follicular rupture. {Center) Mature ovum with axial gradient of pigment and 

 yolk. The vitelline membrane is now present, and the cyst wall of smooth muscle 

 cells is stretched. (Bottom) Ovarian egg partially emerged from its follicle dur- 

 ing ovulation. Note degree of constriction, contraction of cyst wall, and fully 

 developed vitelline membrane around the entire egg. 



