THE M^LE AND FEMALE REPRODUCTIVE ORGANS 1131 



The Corpus Luteum. — According to Clark, ^ the rupture of the 

 Graafian follicle is brought about by complex changes in the vascu- 

 larity of the ovary, leading to a congestion of the entire organ. In 

 consequence of this increased tension, the follicle is pushed far out- 

 ward. The stigma of its outer wall becomes necrotic and bursts, 

 allowing the liquor as well as the ovum and a part of the torn mem- 

 brana granulosa to escape into the tube. The walls of the empty 

 follicle then collapse, but are distended again by blood derived from 

 the vessels of the theca. To begin with, therefore, the corpus luteum 

 is represented by a ruptured Graafian follicle, filled with blood and 

 invested by a layer of yellow lutein cells of the theca. The latter 

 multiply rapidly and presently enter the hemorrhagic extravasate 

 which they occupy completely with the exception of a small central 

 area. Connective tissue strands and blood-vessels follow them in 

 increasing numbers so that the corpus finally assumes the appear- 

 ance of an organized and growing structure. Very soon, however, 

 retrogressive changes set in which terminate in a hyaline degeneration 

 of the lutein cells and their final absorption. This obliteration of the 

 corpus luteum takes place more rapidly in young persons, because the 

 circulation of the adult ovary has lost much of its original vigor. 

 Eventually, the corpora appear merely as small whitish granules 

 resembling scar tissue. They are then known as the corpora fibrosa or 

 albican tia. 2 



It is to be emphasized, however, that it is not real scar tissue; in 

 fact, the reason for the formation of the corpora lutea is to prevent 

 the conversion of the ovarian parenchyma into a tissue of this type 

 which would effectively prevent the formation and discharge of other 

 ova.^ Besides, the corpus luteum seems to furnish an internal secre- 

 tion which is intimately concerned with the future development of the 

 ovum.^ Thus, it has been noted by Frankel that the next succeeding 

 menstruation invariably fails to take place if the corpus luteum has pre- 

 viously been destroyed by means of a cautery. Further evidence to 

 show that it is a temporary gland, is presented by the fact that its 

 atrophy and degeneration are closely connected with the fertilization 

 of the ovum. If the latter is not fertilized, this retrogression will be 

 completed in the course of 2 or 3 weeks, while if it is fertilized, the 

 consummation of this process may require 6 months and longer. For 

 this reason, it is customary to speak of true and false corpora lutea. 

 The former is larger and persists until the development of the ovum is 

 well advanced, whereas the latter is fully reduced within a short time 

 after the menstrual period. According to Miller, it is possible to dis- 

 tinguish between these corpora by histological and micro-chemical 



^ Johns Hopkins Hosp. Rep., 1898. 



2 Frankel, Archiv fur Gynec, Ixviii, 1903, 438, and xci, 1910, 705; also: Meyer, 

 ibid., c, 1913, 1, and Ruge, ibid., c, 1913, 20. 



3 Marshall, Physiol, of Reproduction, London, 1910. 

 * L. Loeb, Jour. Am. Med. Assoc, xlvi, 1906, 416. 



