"220 NOBMAL HISTOLOGY. 



develop in the latter, and eventually the follicle is reduced to a 

 small mass of dense fibrous tissue (corpus album, Fig. 193, k). If 

 pregnancy occurs during the progress of these changes, they are 

 much slower than if pregnancy is absent. In the latter case the 

 epithelium does not become so prominent and the follicle is not so 

 yellow, but passes from the hemorrhagic to the fibrous stage more 

 rapidly (corpus hsemorrhagicum). When pregnancy exists, the 

 lutein cells are more prominent in the composition of the mass and 

 the follicle is more yellow in color (corpus luteum, Figs. 196 and 

 197). The corpus album formed from the corpus luteum is also 

 larger than that derived from the corpus hrcmorrhagicum. 



Fjg. 198. 



thi C 



Section from rabbit's ovary, illustrating the formation of the corpus luteum. (Sobotta.) 

 Recently ruptured Graafian follicle, ke, germinal epithelium; beneath it, the ovarian 

 stroma. Bounding the follicle externally is the fibrous capsule of the follicle. Within 

 this, thi, is a layer of proliferating fibrous tissue, composed of polyhedral cells with round 

 nuclei. Among these are elongated nuclei belonging to endothelial cells springing from 

 the capillaries, and destined to form the walls of future bloodvessels; e, epithelium of 

 the membrana granulosa. Within this are the viscid remains of the liquor folliculi, 



containing a few red l>l L-corpuscles and some epithelial cells detached from the mem- 



brana granulosa, bl, red hi l-corpuscles. This section was prepared from an ovary 



about twenty four hours after coitus, and the development of the layer thi probably 

 took place within that time. 



2. The Fallopian Tube. — The free surface of the Fallopian tube 

 is covered by a serous membrane, continuous with the rest of the 

 peritoneum. This rests upon fibrous tissue, in which the longi- 

 tudinal bundles of smooth muscular tissue constituting the external 



