Bennet Mills Alien 



107 



tures, the point of junction is marked by the persistence of the hase- 

 ment membrane of tubulus rectus and seminiferous tubule. These 

 membranes are soon absorbed and the two structures are in direct con- 

 tinuity with one another. 



Female. — The primitive sex cells are found in all parts of the rete 

 ovarii, yet their distribution is in no sense uniform. The intra- 

 ovarian portion contains great numbers of primitive sex cells, which 

 show a close resemblance to those found in certain regions of the 

 cords of Pfliiger. Associated with these sex cells of the rete are other 

 and smaller cells which are practically identical with certain cells of 

 the cords of Pfliiger destined to form the granulosa of the Graafian 

 follicles. 



As stated above, the primitive sex 

 cells are not by any means confined to 

 the intra-ovarian portion of the rete 

 tissue, yet their number in the por- 

 tion of the rete lying within the me- 

 sonephros is found to become less and 

 less as the distance from the ovary 

 increases. The same principle holds 

 true in the male. 



The medullary cords are greatly re- 

 duced (Text Fig. 3), consisting of 

 clumps of cells containing sex cells in 

 various stages of development, the 

 most advanced being large oocytes 

 with a well-formed layer of granulosa 



cells. Such young follicles are rare j,,^, 3. Transverse section of ovary 

 nnrl icnlafcirl and niesonei>hrJc structures of pigr em- 



duu ifeUidLeu. ^j.yQ Length 13 cm. c, cortex ;/(. p., 



The irinprmo^t pnrl^ of tbp porrls; of hollow cord of Ptiflger: ni., medulla; m. 

 Xiie mueimosi enu^ 01 ine COras 01 ^^ medullary cord; M. d.. Mullerian 



Pfluger are being broken up to form 'ir.^'i', woith^n'duct.^T2^!'"'''^*^ 

 follicles. These follicles are young, 



each consisting of a large oocyte and a single layer of granulosa cells. 

 The oocytes almost invariably contain numbers of fat globules situated 

 in their cytoplasm and especially numerous about the centrosphere, 

 where they appear to congregate, eventually combining to form a single 

 large mass. This appears to be without doubt a process of degeneration, 

 leaving clumps of granulosa cells which persist for some time after the 

 oocytes have disappeared. Not only are these oldest sex cells being 

 destroyed by fatty degeneration, but there is an independent process of 

 karyolysis which destroys great numbers of younger sex cells. In addi- 



