120 G. CARL HUBER 



DEGENERATION AND DEATH OF OVA AT THE END OF 

 THE SEGMENTATION STAGES 



In figure 2, A and B, are presented drawings of typical sec- 

 tions of two morula masses showing complete degeneration and 

 death. The degenerated ovum shown in A, of this figure was 

 obtained from rat No. 52, 4 days, 15 hours, after insemination. 

 In all, eight normal ova were found in the uterus of this rat, 



1 



Fig 2 Ova of the albino rat in late segmentation stages, showing death and 

 dissolution of the constituent cells. X 200. A, rat No. 52, -I days, 15 hours, 

 after the beginning of insemination. B, rat No. 68, 4 days, 1(> hours, after the 

 beginning of the insemination. Tins figure shows an imperfectly developed 

 morula with probable retention of oolemma. 



these showing late morula stages and stages of early blastodermic 

 vesicle formation, three of which were sketched and are shown in 

 A, B, and C of figure 20, Part I. The degenerated ovum here 

 under consideration lies in very close proximity to the normal 

 blastodermic vesicle shown in C of figure 20, Part I. The 

 shallow mucosal pits harboring the two ova are in contiguity. 

 The two contiguous pits resemble each other very much; the 

 mucosa underlying them is in every respect the same, indicating, 

 it would seem, that to a certain stage in development — to the 

 end of segmentation — the development of the degenerated ovum 

 proceeded normally. The degenerated egg-mass measured ap- 

 proximately 80 /i by 50 /x by 40 n- In reaction to stains, it dif- 

 fers markedly from the adjacent normal vesicle. The staining 

 is very pale; cell boundaries are indistinct or lost, and the nuclei 

 scarcely retain any coloring matter. Scattered through the pro- 

 toplasm are found small globular masses, perhaps of lipoid 

 character. Protoplasm and nuclei present evidences of cytolysis 

 and chromatolysis, and have the appearance presented by ne- 

 crotic tissue. Had normal development supervened, both ova 



