156 



W. H. LONGLEY 



The ovarian egg at the end of the period of growth 



The living egg. The living cat's egg has a diameter ranging from 

 0.135-0.150 mm. and is surrounded by a zona 0.012-0.01 '1 mm. 

 in thickness. As compared with mouse and rat eggs, one of the 

 most striking characteristics of the cat's egg is its opacity. This 

 is largely due to the presence of an abundance of highly refractive 

 nutritive globules, which are darkened by osmic acid. They 

 vary from mere points to spheres of a diameter of 0.009 mm. but 

 the most of them approximate a diameter of 0.006 mm. They 



Fig. 4 Degenerating follicle. Ov., egg; M.p., inembrana propria. Note the 

 shape of the egg, the nearly complete absence of granulosa cells between the egg 

 and the inembrana propria, and the incomplete and morphologically imperfect 

 zona and corona. X 95. 



tend to conceal the germinal vesicle, which is spherical, rather 

 difficult to demonstrate, and has a diameter of 0.037 mm. The 

 polarity of the egg is not well marked, i.e., the greater part of 

 the egg seems filled with the nutritive globules, but there is a 

 small cup-shaped depression filled with granular protoplasm at 

 that part of the periphery where the germinal vesicle lies. There 

 is also a clear, superficial layer of like material about 0.015 mm. 

 in thickness. 



