576 MENSTRUATION AND PREGNANCY. 



CHAPTER VI. 



ON THE COEPUS LUTEUM OF MENSTRUATION 

 AND PREGNANCY. 



AFTER the rupture of the Graafian follicle at the menstrual 

 period, a bloody cavity is left in the ovary, which is subsequently 

 obliterated by a kind of granulating process, somewhat similar in 

 character to the healing of an abscess. For the Graafian follicle 

 is intended simply for the formation and growth of the egg. 

 After the egg therefore has arrived at maturity and has been dis- 

 charged, the Graafian follicle has no longer any function to per- 

 form. It then only remains for it to pass through a process of 

 obliteration and atrophy, as an organ which has become useless 

 and obsolete. While undergoing this process, the Graafian follicle 

 is at one time converted into a peculiar, solid, globular body, which 

 is called the corpus luteum ; a name given to it on account of the 

 yellow color which it acquires at a certain period of its formation. 



We shall proceed to describe the corpus luteum in the human 

 species; first, as it follows the ordinary course of development 

 after menstruation ; and secondly, as it is modified in its growth 

 and appearance during the existence of pregnancy. 



I. CORPUS LUTEUM OF MENSTRUATION. 



We have already described, in the preceding chapter, the man- 

 ner in which a Graafian follicle, at each menstrual epoch, swells, 

 protrudes from the surface of the ovary, and at last ruptures and 

 discharges its egg. At the moment of rupture, or immediately 

 after it, an abundant hemorrhage takes place in the human sub- 

 ject from the vessels of the follicle, by which its cavity is filled 

 with blood. This blood coagulates soon after its exudation, as 

 it would do if extravasated in any other part of the body, and 

 the coagulum is retained in the interior of the Graafian follicle. 



