OVARY 



357 



Hensen observed that the fimbrias were in very active motion, sweeping 

 here and there over the surface of the ovary so powerfully that the effect 

 of ciliary action must have been trivial. The ova, surrounded by the 

 mucoid cells of the follicles, adhered more closely to the fimbriae than to 

 the smooth surface of the ovary. Except toward the time of ovulation, 

 Hensen found that the fimbriae were rela- 

 tively inactive (Zeitschr. f. Anat. u. Entw., 

 1875, pp. 213-270). The discharge of the 

 ovum from the follicle is known as ovulation. 



It may be noted that in approaching the 

 peritoneal epithelium, through which the 

 rupture occurs, the follicle must push aside 

 or distend the connective tissue of the tunica 

 albuginea. This is ordinarily a rather weak 

 layer, but it has been suggested (by Rey- 

 nolds) that in some cases it is more highly 

 developed and acts as an obstruction to ovulation. 



After ovulation, blood escapes from the capillaries of the tunica interna 

 and forms a clot within the empty follicle (Fig. 360). This clot is some- 

 times called the corpus hosmorrhagicum. On all sides it is surrounded by 

 the cells of the stratum granulosum, which enlarge and produce a yellow 

 fatty pigment. They form a yellow convoluted zone which may easily 



FIG. 360. OVARY, CUT ACROSS 

 SLIGHTLY REDUCED. 



a., Aperture through which the 

 ovum escaped; c. a., corpus 

 albicans; cl., blood clot in a 

 corpus luteurn of ovulation; 

 th., theca folliculi; v. f.. vesi 

 cular follicle. (After Rieffel.) 



Connective tissue septa. 



Fibrous connective tissue. 



Vacuoles. 



Lutein cells. 



FIG 361. A, PORTION OF A CORPUS LUTEUM OF A RABBIT. B, PORTION OF A CORPUS LUTEUM OF A 



CAT. X 260. 

 In B the lutein; 'cells have become fatty and contain large and small;vacuoles. 



be seen without magnification; the entire structure is then known as the 

 corpus luteum. Vascular strands of connective tissue extend between the 

 lutein cells (Fig. 361) and enter the central clot. The extravasated blood 

 breaks down into granules and hasmatoidin crystals, and is gradually 



