GI-atenSy — Notes on the Human Ovary. 69 



III. — Previous Work. 



The well-known Belgian embryo! ogist, Van cier Strieht, has carefully 

 studied the corpus luteum of the Vespertillio noctula, one of the hats. These 

 were captured in the evenings, on the outskirts of Ghent. Van der Strieht 

 has made a very extensive collection of the ovaries of several species of bats, 

 and his work is of special importance in any discussion on the corpus luteum. 

 Van der Strieht, with reference to the question of the origin of the luteal 

 cells, writes — "En attendant denouveiles reeherches, surtout chez les grands 

 mammiferes, nous restons toujours couvaiucu de I'origine mixte '.' (i.e. from 

 both raembrana granulosa and theca interna). 



The present writer cannot criticise Van der Stricht's opinions, on the basis 

 of the human material he has seen, but, as will be mentioned more fully 

 below, in the case of Ornithorhynchus, there can be no doubt that the luteal 

 cells are derived purely from the membrana granulosa of anatomists (follicle 

 epithelium layer of the zoologist). One must agree that in certain mammals 

 it is very difficult to say whether or not the theca interna cells participate 

 in the formation of the luteal cells. The close approximation to size between 

 follicle epithelial and thecal cells found in many mammals does not apply to 

 Ornithorhynchus. According to Van der Strieht, the corpus luieum of bats 

 is mainly epithelial (granulosa) in origin, though the conjunctive or thecal 

 elements participate, and its products are a serous, "piefatty " (pregraisseux) 

 substance during the histogenic stages of its life-hittoiy and a " lipoid " 

 (lipoide) substance during the longer period of gestation. Van der strieht 

 thus distinguishes two periods of chemical activity in the corpus luteum : his 

 views certainly seem to agree with what Miller finds in the human, where, as 

 I have noted elsewhere, the corpus luteum of pregnancy is supposed to contain 

 neutral fat, which is not present in that of menstruation. Van der Strieht 

 divides theentire life-history of the corpus luteum into three successive phases : 

 (a) A phase of genesis, during which the lutein cells form at the expense of 

 the follicular epithelium (granulosa) and of some interstitial cells and 

 conjunctive cells of the theca interna. During this stage the theca interna 

 also forms the vascular framework of the corpus luteum. The fatty 

 granulations are relatively few at this period, within the luteal cells, (h) A 

 phase characterized by the extraordinary richness of the fat in the protoplasm 

 of the glandular endocrine cells. At this stage the lutein cells begin to grow 

 greatly in volume, and continue doing so right up to the middle period of 

 gestation. Moreover the whole corpus luteum grows gradually, principally 

 through the accumulation of the various products of secretion. During this 



