592 THE STRUCTURE AND DEVELOPMENT 



(fluid coagulum) ; but this is sometimes absent, and it is then 

 very difficult to determine with exactness the inner border of 

 the epithelium. The tissue (t), which forms the greater mass 

 of the ovary at this stage, is formed of solid columns or trabe- 

 culae of epithelial-like cells, which present a very striking re- 

 semblance in size and character to the cells of the germinal 

 epithelium. The protoplasm of these cells stains slightly more 

 deeply with osmic acid than does that of the cells of the germinal 

 epithelium, so that it is rather easier to note a difference between 

 the two tissues in osmic acid than in picric acid specimens. 

 This tissue approaches very closely, and is in many parts in 

 actual contact with the germinal epithelium. Between the 

 columns of it are numerous vascular channels (shewn diagram- 

 matically in my figures) and a few normal stroma cells. This 

 remarkable tissue continues visible through the whole course of 

 the development of the ovary, till comparatively late in life, and 

 during all the earlier stages might easily be supposed to be 

 about to play some part in the development of the ova, or 

 even to be part of the germinal epithelium. It really, however, 

 has nothing to do with the development of the ova, as is 

 easily demonstrated when the true ova begin to be formed. 

 In the later stages, as will be mentioned in the description of 

 those stages, it is separated from the germinal epithelium by 

 a layer of stroma ; though at the two sides of the ovary it 

 is, even in later stages, sometimes in contact with the germinal 

 epithelium. 



In most parts this tissue is definitely confined within the 

 limits of the ovary, and does not extend into the mesentery 

 by which the ovary is attached. It may, however, be traced at 

 the anterior end of the ovary into connection with the walls of 

 the Malpighian bodies, which lie on the inner side of the Wolffian 

 body (vide fig. 35 B), and I have no doubt that it grows out 

 from the walls of these bodies into the ovary. In the male it 

 appears to me to assist in forming, together with cells derived 

 from the germinal epithelium, the seminiferous tubules, the 

 development of which is already fairly advanced by this stage. 

 I shall .speak of it in the sequel as tubuliferous tissue. The 

 points of interest in connection with it concern the male sex, 

 which I hope to deal with in a future paper, but I have no 



