392 THE CORPUS LUTEUM OF DASVUJiUS, 



which Clark and Doering collected their material has already- 

 been commented upon; but apart from this, the words of Clark's 

 description indicate clearly that he is describing the membrana 

 granulosa of an atresic follicle. In Dasyurus the same wholesale 

 disappearance of membrana granulosa is observed, but only in 

 atresic follicles up to a certain stage of ripeness. Doering denies 

 that his isolated human corpus luteum was an atresic one, but 

 owing to the imperfection of his diagrams and the shortness of 

 his description, it is impossible to contradict his somewhat 

 categorical statements. Doering says, too, in the earlier part of 

 his paper, that "in most cases" the membrana granulosa 

 disappears. He omits to mention what becomes of it in the 

 remainder. Kolliker has also lately expressed himself as of the 

 opinion that Sobotta's explanation of the origin of the corpus 

 luteum in the mouse and rabbit does not convince him. He does 

 not mention any of his own researches on the formation of true 

 corpora lutea in the mou.->e, but on the ground that, in his opinion, 

 they are of the same nature as corpora lutea atretica, he defends 

 von Baer's theor}'. 



Against these opinions we must weigh those of such authors 

 sa Sobotta, Stratz, Honore, and van der Stricht, who have 

 recently studied the corpus luteum in all its developmental stages, 

 and described it with great care. They and many others are 

 unanimous in their support of Bischoif's theor3^ It is unnecessary 

 to dilate further on their mode of work, but this alone, in 

 contrast with the compai-atively scanty observations made by the 

 defenders of von Baer's theory, entitles their opinion to the 

 greater weight. 



Turning to the membrana granulosa of Dasyurus, immediately 

 after follicular rupture there is no sign of degeneration or 

 disappearance of the membrana granulosa, and there has been 

 seen and depicted the actual hypertrophy in the cell substance. 

 It has been observed to begin nearest the theca, in many cases, 

 even before the connective tissue has reached the cavity of the 

 follicle. It has also been observed that it is usually well marked 

 before the membrana propria loses its distinctness, and it is 



