366 THE CORPUS LUTEUM OF DASYlTimS, 



posed of meinbranca granulosa and theca folliculi, with its two 

 component parts, the theca interna and theca externa. The main 

 features of his description have been followed by all succeeding 

 authors. He studied the corpus luteum, and attributed its origin 

 to the inner layer or theca interna of the theca folliculi. He 

 took this view on the grounds that the theca interna is thickened 

 before the rupture of the follicle, and that this layer already pos- 

 sessed the characteristic yellow colour due to the so-called 

 *' lutein " granules. He is one of the few authors who studied 

 the earlier developmental stages of the corpus luteum, and did 

 not base his description on a study of corpora lutea near or 

 during the stages of complete development. 



No important communication was made upon this subject until 

 1840; when Patterson, of Edinburgh, brought forward a theory 

 that the corpus luteum had its origin from the hc\3morrhagic con- 

 tents of the recently ruptured follicle. This theory gained the 

 support of Henle, but was never generally accepted. 



In 1842, Bischoff in his work "On the Histoiy of Develop- 

 ment of Ova in the Rabbit " enunciated a new theory that the 

 corpus luteum originated by modification of the cells of the mem- 

 brana granulosa of the Graafian follicle to form the characteristic 

 cells of the corpus luteum. A few years later, in ovaries of the 

 dog, guinea pig and roe, he found confirmation of this theory. 

 Bischoff studied all the stages of the formation of the corpus 

 luteum both early and late, so that his work has a particular 

 value. There are, therefore, excluding Patterson's, two different 

 theories as to the origin and development of the corpus luteum. 

 As time went on, defenders came forward for either theory. As 

 adherents to von Baer's theory, we find Rokitansky, His, Spiegel- 

 berg, Kolliker, Slavjansky, Gegenbauer, Paladino, Nagel, Bonnet, 

 Schottliinder, Minot and others; whilst Ptliiger, Luschka, Wal- 

 deyer, Call and Exner, and others have supported Bischoff's 

 theory. Much of the work was not carried out upon a series of 

 ovaries containing corpora lutea at all stages of development, so 

 that it loses to a certain extent its value. 



