ON SPERMATOGENESIS IN THE RAT. 
355 
protruded from the nucleus ( vide PI. XXII, fig. 2, e and 
11 ). 
I was at first inclined to attribute the appearance of these 
bodies to a process of disintegration of the nuclei and proto- 
plasm of the supporting cells taking place at this stage. If 
this were the case it would be very difficult to understand how 
these cells could be so quickly reproduced, for in the next stage 
of development (fig. 3) the nuclei of the supporting cells are 
fully developed, and present no signs either of growth or of 
degeneration, although a few fatty globules may still be seen 
in their protoplasm. Prof. Schafer, however, pointed out to 
me that the appearance of these globules is probably due to an 
increased nutrition of the supporting cells taking place at this 
time, when they are about to enter upon a new phase of 
activity, and to serve for the support and probably also for the 
nutrition of a fresh crop of spermatozoa ; and this appears 
to me to be the most probable explanation. Apparently the 
same supporting cell serves for the support of several suc- 
cessive crops of spermatozoa. I have not, however, been able 
to make out in what manner this reproduction takes place, and 
can say little about their life-history. 
It is much easier to make out the history of the supporting 
cells in the Elasmobranch testis, which contains in a single trans- 
verse section every stage of development, from the embryonic 
condition to the fully- formed spermatozoa. The result of my 
own investigations on the testis of the dogfish is in agreement 
with the opinion of a Swaeu and Masquelin, that while the 
spermatozoa are derived from primitive male ova, 
the supporting cells are descended from follicular 
cells, corresponding to the cells of the Graafian 
follicle in the ovary. It is probable that the same is the 
case in the mammal, but in order to make out the origin of 
the supporting cells in the mammal it would be necessary to 
trace them back to the embryonic condition. 
The function of the supporting cells appears to be in great 
1 “ £tude sur la spermatogenese,” par A. Svvaen and H. Masquelin, ‘Archives 
de Biologie,’ tom. iv, fasc. 3, 1883. 
