46 BULLETIN OF THE 



slightly granular, stain feebly, and exhibit each a single large (5-10 /x) 

 nucleus, with an even outline and a circular or oval form. When seen 

 in profile, — as in radial sections of the egg with its membrane and 

 granulosa (Plate V. Fig. 3), — a majority of the cells are observed to be 

 very thin, and their nuclei flattened ; but there is occasionally a cell 

 whose nucleus is not so much flattened, and which therefore protrudes 

 beyond the general surface of the granulosa. Radial sections of the 

 ovum with its granulosa are further instructive in showing the rela- 

 tions of the cells to the heads of the villi. Each granulosa cell cor- 

 responds in size to from four to eight villi, but there is no constancy in the 

 position of the cells or their nuclei in reference to the underlying villi. 

 Nothing intervenes, however, between the cells and the villi except 

 occasional artificial spaces. Externally the granulosa is limited by a 

 thin, homogeneous delicate membrane, the membrana propria (th. fol.) 

 of the theca folliculi. 



This is the condition which obtains over all parts of the egg except 

 in the vicinity of the micropylar funnel. Elsewhere the granulosa re- 

 tains great uniformity of thickness. At a considerable distance from 

 the micropyle its cells begin to elongate so that the granulosa grows 

 thicker ; as the cells approach more and more the condition of columnar 

 epithelium they become inclined, their outer ends being directed to- 

 ward the axis of the micopyle (Plate VII. Fig. 1). They still continue 

 to form a layer only a single cell deep until they reach the vicinity of 

 the rapid declivity in the wall of the funnel. Here the cells, having 

 now attained an elongated columnar form, become superposed, and fill 

 completely the micropylar funnel. With a single exception the cells com- 

 posing this mass are fairly similar to each other. They are considerably 

 elongated, irregularly columnar or spindle-shaped, and contain each a 

 single oval nucleus about 10 /a by 8 or 9 /* in diameter. The cells 

 themselves vary from 15/x to 40 fi in length, and are about 10 /x in 

 diameter. When the hardened egg, with its membranes, is removed 

 from the follicle, it often happens that this conical plug of granulosa 

 cells is left with the rest of the granulosa in the follicle. But even 

 when the majority of the granulosa cells of the plug are thus removed 

 from the funnel, there is usually left behind a single one which is unlike 

 the others. It occupies the bottom of the funnel, which it completely 

 fills, and is much larger than any other of the granulosa cells (m py. cl. 

 Plate IV. Figs. 1, 4, 5, Plate V. Fig. 2, Plate VII. Fig. 2). 



When I first became aware of the existence of such a cell it was from 

 the study of radial sections of a recently deposited egg in which a 



