492 H. L. Wieman. 



gives another view of the degenerated area. From these it can be 

 seen that throughout the greater part of this region all trace of 

 cellular structure has disappeared, the cells having been replaced 

 by clumps of material of various sizes, deeply stained by either 

 iron-alum-haematoxylin or basic anilin dyes. The mass is 

 bounded by a membrane of flattened epithelial cells. The term- 

 inal cap of cells (fig. 8, ex.) has become reduced in size; it no longer 

 protrudes from the surface and the outlines of the cells are dis- 

 tinctly marked by the presence of a deeply staining substance in 

 their periphery, which together with their shrivelled appearance 

 indicates that these cells likewise are undergoing atrophy. 



In the paper referred to before the deeply staining particles 

 of the degenerated region were looked upon as representing the 

 more solid parts of the degenerated cells — it being assumed 

 that the more fluid parts had been expressed into the cavity of 

 the testis as a result of accompaniment of the process of contrac- 

 tion. It can be readily understood that as the degenerated mass 

 is compressed toward the distal side of the testis, the central 

 cavity of the latter comes into existence. The cavity however 

 almost immediately becomes filled with mature spermatozoa, set 

 free by the rupture of the surrounding follicles. These facts 

 called forth the suggestion that the more fluid products of the 

 degenerated cells serve as a nutritive substance, or perhaps a 

 liquid medium, for the spermatozoa. 



It is obvious that this peculiar cytological condition is differ- 

 ent in every way from the degenerated cells that have been de- 

 scribed in the testis of spiders. According to Wallace, in Agalena 

 naevia degenerated cells or cell fragments are found enveloping 

 the spermatozoa in the sperm ducts, and are said to come from at 

 least four different sources: (1) broken down walls of empty 

 cysts, (2) cell bodies from which ripe spermatozoa have escaped, 

 (3) ''connecting bodies" of sister spermatids and their contained 

 mid-bodies, (4) large oval cells which resemble the rolled up sper- 

 matozoa in size and outline. 



In Leptinotarsa, so far as I have been able to determine, only 

 epithelial cells derived from the terminal cap participate in the 



