146 HALSEY J. BAGG 
lium. The optic nerve was extremely small, not more than one- 
seri? the normal dimensions. 
. The testes of the radiated animals were decidedly atrophic, 
zs a comparison with the normal is shown in the photograph 
in figure 15. The diameters of the testicle alone (minus the 
epididymis) of the experimental animal was 14 mm. for the length 
and 7 mm. for the width, while the control measurements from 
normal animals of the same age and weight and with the same 
method of fixation were 21 mm. for the length and 11.5 mm. for 
the width. ‘The epididymis of the radiated testis was practically 
missing. A small portion of the tail remained, but the head and 
body of the epididymis had failed to develop. Histological 
examination shows that there is little evidence of spermatogenesis. 
Some tubules seem to contain imperfect spermatoblasts and 
forming spermatozoa, but the great majority of tubules show 
complete degeneration and loss of epithelial cells, and contain 
loose granular material, which in places is calcified. Some 
spermatic tubules are greatly dilated and filled with granular 
material. Very few interstitial cells are visible. 
The ovary of the radiated animals was reduced to one-fourth 
or one-fifth the normal size. The graffian follicles were entirely 
missing. “Groups of lutein cells persisted in small numbers, but 
showed marked hydropic degeneration. Some of the large 
vessels about the ovary were sclerosed. 
g. The liver, kidney, lungs, spleen, and the other organs were 
examined, but showed no pathological disturbance. 
CONTROL GROUP 
Pregnant rats of the same stock, the same age and weight, 
were injected subcutaneously and intravenously with equal 
amounts of solutions that previously had been strongly radio- 
active, but were allowed to ‘decay,’ until they had lost their 
radio-activity. These experiments gave absolutely negative 
results. As a control to the gamma-ray experiments, pregnant 
rats, sisters of the treated animals, were allowed to breed under 
exactly the same experimental conditions. No abnormal young 
were observed. 
