RADIUM IRRADIATION AND DEVELOPMENT 149 
spinal-cord, and subcutaneous extravasations. These extravasa- 
tions were markedly similar to those already described for the 
series of solution treatments. The liver in these animals showed 
a fatty degeneration of the hepatic cells similar to the condition 
reported by Mills (17) after exposing a series of mice to gamma- 
ray radiation. The only other pathological change noted in 
these embryos was a desquamation of the lining cells of the 
intestinal mucosa. This observation is in line with the results 
emphasized by Hall and Whipple (18) in their experiments on 
Roentgen-ray intoxication in dogs. 
While the animals described above died after showing acute 
reactions certain of their litter mates (half of the litter) continued 
to develop apparently normally. This difference in reaction may 
possibly be due to individual variability or tolerance for the 
radiation, but it probably can be explained by the fact that cer- 
tain embryos were slightly farther away from the source of 
radiation than others, and as the intensity of radiation varies 
inversely as the square of the distance, even such slight differences 
in distances that did exist would be sufficient to subject the 
embryos to a considerable range in intensity of radiation. This 
is especially important in this case because the source of radiation 
was only 1 em. from the body wall of the mother. The quality 
of radiation, however, remained the same for all the embryos. 
It was soon apparent that the animals that lived over the ten- 
day period had not completely escaped the effect of theradiation, 
as was shown by a suppression of the full development of the 
eyes. Eye defects were noted, such as opaqueness of the pupil, 
atrophy of the lens, and closing of the lids, which resulted in 
complete blindness. These animals grew to a normal size, suc- 
cessfully competed with their cage mates for food, and showed 
absolutely no abnormal neurological condition, except those 
clearly incident to blindness. At autopsy, in some cases over a 
year after birth, very decided developmental arrests were noted 
in the structure of the brain. All grades of such maldevelopment 
were noted in the condition of the neopallium, from merely a 
decrease in the size of the hemispheres, which permitted the 
corpora quadrigemina to be clearly visible from above, to a more 
THE AMERICAN JOURNAL OF ANATOMY, VOL. 30, NO. 1 
