REPRODUCTIVE ORGANS IN THE FEMALE. 313 



cells and connective-tissue cells. If the ovum be- 

 comes fertilized and pregnancy follows, the corpus 

 luteum continues to grow until it becomes many 

 times larger than the original Graafian follicle, causing 

 a rounded elevation at that point on the surface of 

 the ovary. This kind is called a true corpus luteum. 

 On the other hand, if the ovum is not fertilized the 

 corpus luteum shrinks and becomes smaller than the 

 original follicle. This kind is called a false corpus 

 luteum. The corpus luteum is at first well defined 

 by the investing follicular theca, but after a time its 

 limits are less distinct, so that as age advances the 

 ovarian stroma becomes gradually pervaded with 

 cells like those of the corpora lutea. 



THE FALLOPIAN TUBES. 



The Fallopian tubes are two ducts for the passage 

 of ova from the ovary to the uterus. They differ 

 from the ducts of other glandular organs in being 

 detached from the organs whose secretions they con- 

 vey. They are from four to five inches long and 

 pass almost horizontally outwards from the fundus 

 of the uterus. When they reach the ovary they 

 ascend along the pelvic floor and nearly encircle each 

 organ, passing up the external and down the internal 

 or mesial margins. Each tube is enclosed in the free 

 margin of the broad ligament, which is a peritoneal 

 fold that also contains the round ligament of the 

 uterus, the ovary, parovarium, and numerous blood- 

 and lymph-vessels. 



For descriptive purposes each duct is divided into 

 an isthmus, an ampulla, a neck, and a fimbriated ex- 



