Gi-ATENBY — Notes on the Human Ovary. 8^ 



and to a less extent certain other "fatty" substances, have the pnwer of 

 reducing osmic acid and also giving the Sudan III test. In vitro tesis are 

 much more reliable than mierochemical ones, and before one could decide tlie 

 nature of any cell granules, one would need to use all the latest methods. 

 Corner and certain other observers, on the slenderest evidence, conclude that 

 they have been dealing with fat. As a matter of fact, ordinary medullated 

 nerve goes black in osmic acid, and does not contain a trace of neutral fat. 

 This should serve as a warning against rushing into conclusions as to the 

 microcb.emical nature of intra-cellular granules. 



The difficulty of the subject cannot be overestimated ; and until 

 biochemists provide the zoologist with, firstly, a clear account of the chemistry 

 of the fatty and lipoid bodies of the cell, and then with mierochemical methods 

 for their detection, there will be little advance from the cytological side. 



VII.— On the two Eegions of the Cavity of the Corpus Luteum. 



The human corpus luteum herein described, like that of many mammals, 

 exhibits two regions in its interior— one filled by a plug of connective tissue 

 formed by invading fibroblasts (PL III, iig. 1, ct. PI. V, fig. 8), the other 

 filled by a coagulable gelatinous fluid (PI. Ill, fig. 1. cc). The coagulable 

 fluid in the cavity cc is probably different from that of the antrum folliculi, 

 and when preserved in formalin and stained in iron haematoxylin, it shows 

 as a mass of fine threads. The replacement of the liquor folliculi by a new 

 fluid is regarded by Van der Stricht as evidence of a serous secretion from 

 the follicle cells. The new fluid might be lymph reinforced by some denser 

 material, but there is little doubt that it is not pure lymph alone. This 

 seems to support Van der Stricht's view. 



In PI. V, fig. 10, is a microphoto of the edge of the cavity cc, in 

 PI. Ill, fig. 1, and coagulum Cc) is well shown. Wandering into this cavity 

 are numerous fibroblasts (/j and leucocytes (b). In this connexion I may 

 mention that I have found a cavity in the corpus luteum verum of both cows 

 and ewes : the contained fluid ga\e a dense precipitate with absolute alcohol, 

 and was quite different from lymph. Such cavities are present in about 

 5 per cent, of the cow corpora lutea examined by me. In many of the 

 corpora lutea of the cow, sheep, pig, and of the smaller mammals, no such 

 cavity occurs, and, in view of this, it is difficult to believe that great 

 importance should be attached to its presence in the human. 



"VIII. — Discussion. 



In this paper among the new points brought forward for the first time are 

 the description of the stellate theca interna cells, and the account of the 



