Cell Changes in the Testis due to X Rays. 
257 
ment of archoplasmic vesicles, inconsiderable in size, is equally rare. 
On the other hand we have not observed enlargement of intranuclear 
body vacuoles, nor have we encountered multipolar or irregulär mitoses 
or multivacuolated cell masses. 
Changes produced in the testis by the action of X rays. 
The ultimate and penultimate changes in the testis resulting from 
the action of X rays have already been described on pages 9 and 10. If 
the testis is examined immediately after a single exposure to X rays, 
of duration and intensity sufficient to cause within a fortnight consider- 
able destruction of seminal epithelium (e. g. seven Saboraud units) no 
changes are observed. After the lapse of 24 hours however marked changes 
become observable with the higher powers of the microscope, though 
with the lower powers no striking alteration in the aspect of the semini- 
ferous tubules may be noticeable. Subsequently, changes in part re- 
sembling, but shghter in degree than those described above as constitut- 
ing the penultimate stage, are met with. Some difficulty is experienced 
in defining the time relations of the changes about to be described, since 
the same amount of exposure to X rays does not always produce an equal 
degree of injury of the seminal cells. In the absence of more precise 
determination of the average periods of time required for the production 
of the degenerative changes observed, the actual time elapsing in indi- 
vidual experiments between exposure to X rays (in a few cases four 
hours, usually sixty to ninety minutes ; cp. p. 249) and examination of the 
condition of the seminal tubules is given 1 ) in the following description, 
which will be taken in the following order: in the first place a brief re- 
ference voll be made to the condition of the connective tissue of the testis, 
next the changes occurring, at different periods after exposure, in the 
individual cells of the seminiferous tubules (cells of Sertoli, spermato- 
cytes of the first order, spermatocytes of the second order, spermatids, 
spermatozoa) will be detailed ; then, in the next section, these changes 
will be recapitulated in respect of individual cell structures and cell pro- 
ducts; and finaJly, in the last section, the characters of the changes 
produced by X rays will be considered from the standpoint of their phy- 
siological aspect. 
The circumstance that slight degenerative changes are encountered 
in testes which have not been exposed to X rays, renders it necessary, 
1 ) These periods of time refer therefore exclusively to actual experimental results 
and have not necessarily any general application. 
