1880.] 



in the common Fowl and in the Rabbit. 



249 



" Ei-schlauch." The germinal vesicle seems to be connected by fine 

 lines with two small nuclei at the periphery of the vitellus. 

 Fig. 16. Small Graafian follicle, similar to that represented in Fig. 14. At one side 

 two nuclei are seen in the peripheral part of the vitellus. The area in 

 which they lie is marked off by a line from the rest of the vitellus. 

 Indistinct striae pass from here towards the germinal vesicle. 570 

 diameters. 



Fig. 17. Graafian follicle, with a complete inner layer of follicular epithelium. This 

 differs markedly from the outer layer in the appearance and arrange- 

 ment of the cells. The irregular outline of the ovum is to be re- 

 marked. Drawn under a magnifying power of about 350 diameters. 



Fig. 18. Small follicle, with single layer of epithelium. Germinal vesicle presents a 

 bulging on that side of it which is lurned towards a nucleus-like body 

 in the periphery of the vitellus. The figure is otherwise like figs. 14 

 and 16, but somewhat less magnified. 



Fig. 19. Small follicle, showing three cells in periphery of vitellus. Magnified about 

 240 diameters. 



Fig. 20. A Graafian follicle, much further advanced towards maturity than any of 

 those above represented. The cells of the inner layer of the follicular 

 epithelium have by this time assumed their characteristic columnar 

 form and radiating arrangement. The macula germinativa is, as before 

 mentioned, formed of a homogeneous matrix, with dark granules 

 imbedded in it. The zona pellucida is now distinct. Magnified 570 

 diameters. 



Fig. 21. Small follicle, with ovum. An intra-nuclear network connects a small 

 germinal spot with the wall of the vesicle. The vitellus is in the form 

 of a network of filaments. Magnified about 200 diameters. 



Fig. 22. Small follicle, with outer layer of epithelium complete and a few cells of 

 inner layer formed between this and the ovum. The germinal vesicle 

 contains three small germinal spots united by a network. The vitellus 

 atao exhibits a network of delicate filaments. Magnified about 450 

 diameters. 



Fig. 23 a. A small portion of the zona jpellucida of an ovum from a large Graafian 

 follicle, together with some of the cells of the discus proligerus, which 

 are mixed with it. A layer of granular substance is seen to intervene 

 between these cells and the outer surface of the zona, and granules 

 similar to those of this substance can be traced through pores in the 

 zona into continuity with the granules of the vitellus. Drawn under 

 a power of about 750 diameters. 



Fig. 23 h, Germinal vesicle of an ovum from a large follicle. 



m. v. Membrane of vesicle. The macidata germinativa is in the form of a 

 number of spherical globules, one of which is much larger than the 

 rest. The remainder of the contents of the vesicle is clear. 



Fig. 24. A row of four so-called " nests" from near the surface of the ovary of a 

 young rabbit. The egg-cell has not yet increased in size beyond the 

 other cells of the nest. Magnified about 450 diameters. 



Figs. 25 and 26. Two very small follicles, with youug ova. In fig. 26 two germinal 

 vesicles are seen. From the same ovary and magnified to the same 

 extent as fig. 24. 



Figs. 27 to 35 are from sections of the bitch's ovary. 



Figs. 27, 28, and 29 represent small Graafian follicles, containing young ova. In 

 each the germinal vesicle is seen to contain an intra-vesicular net- 

 work, and the vitellus is collected into a patch which is in contact 



