HAGUE: SPERMATOZOA AND SERTOLI CELLS. 135 



ning to move outward. In both these conditions each Sertoli 

 cell is almost invariably completely surrounded by sperma- 

 tocytes. In the latter case sections of tubules with the lengths 

 of the lumens extending across the entire field, with the low- 

 power, were used and no spermatozoa were seen in the lumens, 

 or had even reached the inner portion of the Sertoli cells. Counts 

 of very early stages of spermatozoa were very difficult, because 

 they are less clearly outlined, and the Sertoli cells are thicker, 

 more branching, and come in contact with each other about the 

 lumen, thus making the groups of immature spermatozoa less 

 distinct than the mature groups. The spermatids are not suffi- 

 ciently grouped to give reliable accounts. 



In all the following counts the microscope was carefully 

 focused each time to see that the cell was complete. First 

 mature spermatozoa were counted in longitudinal sections of 

 tubules, in the lumens of which there were no spermatozoa; 

 neither had the spermatozoa advanced to the inner portion of 

 the Sertoli cells. Thus none can have escaped. The following 

 groups of spermatozoa in Sertoli cells were counted in sections 

 30, 35, and 40 micra thick : 



10 groups of 6 spermatozoa. 

 30 groups of 7 spermatozoa. 

 45 groups of 8 spermatozoa. 

 35 groups of 9 spermatozoa. 



3 groups of 10 spermatozoa. 



In sections of the same thickness groups of spermatozoa 

 which had just reached or were approaching the bases of the 

 Sertoli cells were counted, and the following results obtained: 



9 groups of 6 spermatozoa. 



26 groups of 7 spermatozoa. 



24 groups of 8 spermatozoa. 

 16 groups of 9 spermtaozoa. 



5 groups of 10 spermatozoa. 



4 groups of 11 spermatozoa. 



Finally very early spermatozoa were counted in sections 40 



micra thick, most of which were stained with iron hematoxylin 



and counterstained with eosin. The counts of these immature 



spermatozoa are as follows : 



10 groups of 6 spermatozoa. 

 23 groups of 7 spermatozoa. 



27 groups of 8 spermatozoa. 



25 groups of 9 spermatozoa. 

 10 groups of 10 spermatozoa. 



2 groups of 11 spermatozoa. 

 1 group of 12 spermatozoa. 



