THE FOLLICLE SACS OF THE AMPHIBIAN OVARY. 



249 



sectioned a large number of eggs taken from the body cavity, 

 I have never found a single one in which the polar spindle was 

 not fully formed with the chromosomes arranged along the 

 spindle fibers. Brandt suggests that there may be an active con- 



0. W. 



FIG. 3. Longitudinal section of a follicle sac just after the egg has passed into 

 the body cavity. C, blood corpuscles; O. W., ovary wall. Zeiss obj., D. Oc. 4. 



traction of the follicle sac when the egg is ready to leave the 

 ovary, and that this contraction stretches the base of the follicle 

 and causes a rupture. How such a contraction takes place with- 

 out the presence of muscles in the walls of the follicle sac is not 

 at all clear. It seems to me that the rupture of the ovarian wall 

 is more likely to be due to some activity on the part of the egg 



