456 MONTGOMERY. [Vol. XV. 



probably represents the commencement of such a degeneration, 

 there lies close to the nucleus what seems to be a much smaller 

 nucleus, or a portion of one ; and I have found all intermediate 

 stages between such a body, which is granular and stains with 

 haemato.xylin, and the body reproduced in Fig. 253, which 

 appears nearly homogeneous and stains with eosin. These 

 bodies then seem to be degenerated or cast-off portions of 

 nuclei. We might conclude also that the cells in which these 

 structures are found, are themselves fated not to develop into 

 egg cells, even if they are not degenerating ; for no such bodies 

 are to be seen in the cytoplasm of the true egg cells. 



These peritoneal cells have the morphological value of ovo- 

 gonia. Those which are destined to become ova seem to 

 become detached from the pseudoepithelial connection, but in 

 such a way that they do not become detached singly, but 

 portions, each of which is composed of a number of cells, 

 become loosened from the epithelium. Thus the earliest ovo- 

 genetic stages are to be found in strings of cells arranged 

 radially around a common longitudinal axis, each such string of 

 cells situated free in the body cavity (Fig. 270 represents a 

 portion of such a string). At the one end of such a cellular 

 string lie, densely grouped, the numerous mitoses of the 

 ovogonic stages, while the remaining portion of the string is 

 usually composed of young ova, sensu strictiori. I have never 

 found mitoses in cells which lie singly in the body cavity. 



The first change noticeable in the ovogonium leading to the 

 formation of the ovum consists in (i) the increase in the size 

 of it and of its nucleus, and (2) in its cytoplasm gradually stain- 

 ing with haematoxylin. This deep blue staining of the cyto- 

 plasm, accompanied by its increasing density and the loss of the 

 vacuoles in it, continues from now on until yolk granules begin 

 to arise in it, when the cytoplasm commences to stain faintly 

 with eosin and loses its dense structure. At the conclusion of 

 the ovogonium rest stage the nucleolus has increased a little 

 in size, accompanying the growth of the nucleus. 



The next stage is a mitosis. Whether there is more than 

 one mitotic generation separating the ovogonium from the 

 ovum I have not been able to determine; the slight differences 



