Cell Changes in the Testis due to X Rays. 
255 
axial filament in its basal portion. In the cast-off cytoplasm the masses 
of fatty material already present increase still further, becoming very 
conspicuous objects (Fig. 32). 
In the above account the formation of spermatozoa has been described 
in some detail owing to the important bearing it has upon some of the 
chief degenerative processes, which are set up by the application of X rays. 
We have, however, omitted reference to the formation of the mitochon- 
drial sheath and to minor points concerning the acrosome and cephalic 
cap, for which the reader is referred to Duesberg’s writings 1 ). 
The foot cells or cells of Sertoli now remain to be described (Fig. 1). 
These are large cells with a broad base applied to the basement mem- 
brane of the seminiferous tubule, the apical portion of the cell extending 
towards the lumen of the seminiferous tubule. The foot cells presents 
a large nucleus, the chromatin of which is distributed in the form of 
very fine granulös of uniform size, no clear indication of linin Strands 
being recognizable. In the course of their development the spermatids 
become attached to the foot cells by their cephalic extremities, their 
tails projecting freely into the lumen of the seminiferous tubule. Each 
foot cell ultimately Supports a large number of spermatozoa, which are 
very closely applied to each other so as to constitute a sheath like Col- 
lection. The foot cells can be distinguished from adjacent spermatogonia 
by their greater size, clear nucleus, large nucleolus, and finely granulär 
chromatin; in the spermatogonia the chromatin is conspicuous by its 
aggregation into four or more masses connected by fine linin Strands. 
Degeneration of seminal cells. This occurs in some degree 
•in healthy testes and assumes two forms: 1. necrosis; 2. formation of 
fatty globides. 
1. Necrosis appears to affect only spermatocytes of the first order. 
In healthy testes some tubules are quite free from this condition, while 
others exhibit it in moderate amount. Only a very small fraction of 
the spermatocytes of the first order however exhibit this change unter 
normal conditions. Necrosis is most readily recognizable in stained 
sections when it is observed that the cytoplasm of the cell takes up basic 
dyes instead of acid dyes. It is not so well seen in tissues hardened in 
osmic acid but otherwise unstained; in such cases the cytoplasm assumes 
a cloudy character. The necrosis involves the nucleoplasm as well as 
the cytoplasm and affects cells which are in the mitotic condition as 
well as cells which are not dividing. In the latter case the nuclear mem- 
x ) Loc. cit. 
