132 KANSAS UNIVERSITY SCIENCE BULLETIN. 



The only statements of ratios of spermatozoa to Sertoli cells, 

 thus far found, are those of Montgomery and Winiwarther. 

 Both of these base their figures on the proportion — 3 to 1 — 

 of spermatogonia without rods to spermatogonia with rods, 

 or crystals. They agree that from the cells containing rods 

 Sertoli cells develop. However, Winiwarther says that the 

 three cells with rods develop into primary spermatocytes, 

 while Montgomery asserts that they divide before becoming 

 primary spermatocytes. The latter thus gets the ratio of 24 

 spermatozoa to one Sertoli cell, and the former the ratio of 12 

 spermatozoa to each Sertoli cell. 



After comparatively little study of mature Sertoli cells and 

 spermatozoa in the rat, the conclusion was reached that there 

 could not be as many as 24 spermatozoa to each Sertoli cell. 

 Then the theory that there are 12 spermatozoa to each Sertoli 

 cell was assumed, but this too had to be abandoned, since the 

 counts showed smaller numbers. 



In the human material available the spermatozoa have 

 nearly all been expelled. Accordingly, distinct Sertoli cells 

 filled with spermatozoa are hard to find. Three cells were 

 found in which there were twelve spermatozoa, a few in which 

 there were ten or eleven, and more in which there were eight 

 or nine spermatozoa. However, the writer has no way of 

 telling whether or not the Sertoli cells are complete, for the 

 sections are only 10 micra thick, with the exception of the 

 celloidin ones. The few spermatids are not grouped together 

 thus making counts impossible. 



The rat testes were taken from two animals, and were in a 

 condition of very active production of spermatozoa. In the 

 rat the mature Sertoli cells are long and slender, and have the 

 appearance of striations. The spermatocytes between the 

 Sertoli cells are small and identical. Consequently tracing a 

 Sertoli cell from one section to another is extremely difficult. 

 Sections varying in thickness from 6 to 24 micra were stained 

 lightly with Delafield's hsematoxylin or hsemalum. The sper- 

 matozoa, however, took the stain so lightly that they can not 

 be distinguished when packed in the cells. Sections 15 micra 

 thick stained with iron haematoxlyin are so much better, 

 that some counts were made from them, also from a section of 

 tissue preserved in Flemming's fluid, but which was already 

 prepared. Thinking that there were twelve spermatozoa in 



