156 MUNSON. [Vol. XV. 



ery of the egg, where they are continuous with a small mass 

 of hyaline protoplasm. In one or two cases, stainable bodies 

 suggesting chromosomes have been seen in the midst of this 

 radial striation. 



In one case, a mass of hyaline protoplasm, free from yolk 

 and having the form of a spindle, was observed imbedded in 

 the yolk some little distance below the egg membrane (PI. XIII, 

 Fig. 17). The latter showed a perforation running radially 

 through it at this point, suggesting a micropyle. As this is the 

 only trace of such a structure that has been observed, it cannot 

 be definitely stated to be a micropyle. The lumen of the 

 perforation was occupied by a number of small yolk granules. 



In the case of other eggs, various causes have been assigned 

 for the movement of the germinal vesicle towards the periph- 

 ery. 



The yolk accumulating at one pole continues to gradually 

 increase until that pole in which yolk does not accumulate and 

 with which the germinal vesicle is connected, becomes more 

 and more flattened out (PL XIII, Figs. 11, 14; PI. XVI, Fig. 

 104), the hyaline spongy protoplasm, of which it is composed, 

 being forced more and more over the surface of the &gg as the 

 vegetative pole increases. This process continuing, the germi- 

 nal vesicle soon comes to lie under the cap previously described. 

 Owing to the growth of the yolk at one pole, the germinal 

 vesicle and its surrounding hyaline protoplasm, originally near 

 the center of the egg (PI. XIV, Figs. 20, 24), becomes more 

 and more displaced, the internal portion becoming turned out, 

 so to speak. It might perhaps be designated as an evagination, 

 somewhat like the finger of a glove when straightened out after 

 being turned in on itself. 



The nucleolus. — In the stages of the oogonia preceding the 

 final division, resulting in the formation of a follicle, no trace 

 of a nucleolus can be discerned (PI. XIV, Figs. 33, 35, 37). It 

 is first seen in the oocyte, at the time when the latter has 

 commenced to increase in size. As we have seen, the chromatin 

 at this time loses many of its previous characteristics, both with 

 regard to chemical reactions and general appearance. The 

 chromatin bodies, so far as they retain their regular form. 



