BY F. P. SANDES. 391 



case be found tlie corpus luteum a little further advanced than in 

 another. 



The amount of central tissue in the fully formed corpus luteum 

 varies. Sometimes its interstices are completely filled with cells 

 of the corpus luteum; at other times there persists for some time 

 a cavity in the centre whose only content is connective tissue 

 with occasional blood vessels. 



In the preceding part of this section the chief points in con- 

 nection with the tlieca folliculi have been shortly discussed. 

 There are, however, in the case of the membrana granulosa other 

 points concerning which authors are at variance. 



In Dasyurus the membrana granulosa, unlike the theca folliculi, 

 is throughout its existence characterised by active change. This 

 is early evidenced by the multiplication of its layers, by the 

 occurrence of karyokinetic figures in the membranse granulosa^ 

 of the primordial and Graatian follicles, and by the general 

 characters of their epithelial cells. It would not, therefore, be 

 surprising to find that, after the follicular rupture, the membrana 

 granulosa should persist and play a part in the formation of the 

 corpus luteum. Many authors deny that this is so. Nagel, for 

 instance, says that — in man — the membrana granulosa disappears 

 absolutely. Eiihler, too, in his preliminary note says the same, 

 though at present his proofs are not forthcoming; whilst Kreis 

 and others maintain that in man the cells of the membrana 

 granulosa multiply or hypertrophy to form the characteristic cells 

 of the corpus luteum. There is, therefore, a difference between 

 observers who have taken man as the basis of their observations. 

 Clark and Doering also deny that the membrana granulosa forms 

 the characteristic cells of the corpus luteum. Clark says that (in 

 the swine) a few of his preparations showed some epithelium, 

 others almost none; and from this he concludes that the membrana 

 granulosa completel}' disappears at the time of, or soon after 

 rupture of the follicle. This is all the notice that Clark deems 

 necessar}' to give to the description of a process whose study is 

 so important to thoroughly understand this question, and he does 

 not show a single figure to illustrate it. The haphazard way in 



