THE FEMALE 



53 



Photograph of the open body cavity of an actively ovulating female frog showing 

 the entrance of an egg into the ostium. 



literally squeezed from the follicle, through a small aperture. 

 The process looks like an Amoeba crawling through an inadequate 

 hole. Ovulation (rupture and emergence of the egg) takes several 

 minutes at laboratory temperatures, and is not accompanied by 

 hemorrhage. By the time the egg reaches the ostium (within 2 hours), 

 as the result of ciliary propulsion, it is again spherical. 



Ciliary currents alone force the egg into the ostium and oviduct. 

 The ostial opening is very elastic and does not respond to the respira- 



(Continued from opposite page.) 

 gence and adjacerrt empty follicles. (Center) Egg about to drop free into the 

 body cavity, showing degree of constriction by the follicular opening. (Bottom) 

 Excised follicles of an ovulating frog continuing the process of emergence of 

 eggs. Note the plasticity of the egg at this time. 



