RADIUM IRRADIATION AND DEVELOPMENT 139 
to fullterm. Thirty-four animals were injected between 5 and 7 
days before mating; seventeen, 10 to 14 days before, and fifteen, 
20 days before mating. 
Only three litters in this group showed abnormal young. The 
most interesting was a litter of seven, in which case the female 
was treated with 4.2 mc., 22 days previous to fertilization, and 
the foetuses, approximately 16 days old, showed very pronounced 
areas of extravasation, which in one case (fig. 4) covered a large 
area on one side of the head and a few small scattered areas on 
the other side. ‘These areas were not only along the dorsal mid- 
line, but also on the lateral surfaces of the body as well (fig. 5). 
The lesions were much more widely distributed and more variable 
in size than in the cases recorded under section I. Although the 
conditions that produced these results were repeated many times, 
the above is the only case where positive data were obtained. 
Usually the female had either been rendered sterile or the young 
were killed and absorbed during early stages. There were two 
other cases, however, where young were found with haemorrhagie 
areas, and these occurred in a group of females that were treated 
seven days before mating. Female 85 was given a dose of 6.6 me. 
on November 7, 1919. It was mated on November 14th, and 
represented as a lighter area in the upper portion of the drawing. Female mated 
April 22, 1919, injected May 7th, killed May 16th. Dose = 4.6 mc. (subeutane- 
ous). 
Fig. 2 A stalked sac partly dissected from the uterus, showing the remnants 
of a former embryo and placenta. Female mated April 22nd, injected May 7th, 
killed May 16th. Dose = 4.8 mc. (subcutaneous). 
Fig. 3. This is a dorsal view of a rat embryo, showing a characteristic area of 
extravasation due to the treatment of the mother during pregnancy. Female 
mated April 22nd, injected May 7th, killed May 9th, at which time seven foetuses 
were found about fifteen days in development. Two of the litter were macerated 
and two absorbed. Dose = 4.9 me. (subcutaneous). 
Fig. 4 Areas of extravasation are shown in the two views of this embryo, 
similar to the condition shown in figure 3, but in this case resulting from treating 
the mother twenty-two days before fertilization. There are a few small scattered 
areas over the right side of the head and a large area of extravasation on the left 
side. Female injected April 22nd, mated May 12th, killed May 30th. Seven 
foetuses were found, fifteen to sixteen days old. Dose = 4.2 mc. (subcutaneous). 
Fig. 5 These are three views of another foetus, a litter mate of the one shown 
in figure 4, showing the wide distribution of the extravasated areas over both sides 
and back of the animal. The experimental conditions are the same as for figure 4. 
