Cell Changes in the Testis due to X Rays. 
243 
Page 
Intranuclear body 265 
Chromatoid body, archoplasmic vesicle, archoplasm, centrosomes, vacuoles 265 
Fat globules 268 
Debris 268 
Charaeters of the changes in the cells of the testis, 
resulting from the action of X rays, considered 
from the physiological stand point: Introduction . 268 
Disturbance of cell division 269 
Disturbance of cell development 271 
Disturbance of cell nutrition 271 
Description of the Illustrations 271 
Introduction. 
The injuries produced by the action of X rays upon living tissues 
present a pecidiar interest, owing to the circumstance that such injury 
when inflicted upon the surface epitheüum of man, has, in a number of 
cases been followed at a later period by epithelioma in the area of injury. 
In consequence of the interest thus aroused the changes resulting from 
the application of X rays have been studied by various observers, espe- 
cially in respect of the skin, the spieen, and the testis, the investigation 
being in part undertaken with the object of determining the degree to 
which different tissues are liable to injury by these rays, and the working 
conditions under which such injuries are likely to occur in practice, so 
that thereby the hmitations of their safe employment as a therapeutic 
measure may be ascertained. The study of the resulting structural 
changes has, however, been largely carried out under the restrictions 
and hmitations incidental to the use of material obtained from injuries 
produced unintentionally or accidentally during the employment of X 
rays. Their action upon living tissues has also been studied in ex- 
perimental lesions, but still further investigation is necessary in order 
to determine the general principles underlying their action, and in this 
connection it is essential that full advantage should be taken of the great 
advances, which, in recent years have been made in the technique of 
cytological research. As a further study of the changes induced in the 
testis by X rays appeared to be likely to be exceptionahy fruitful, it 
was determined to undertake research in the first instance in this direc- 
tion. Probably in no other organ do cells present so large a series of 
changes in the course of their growth as do those of the testis, and it 
is an exceptionahy fortunate circumstance that the various stages of 
