206 M. F. GUYER AND E. A. SMITH 
Next, 4A1, was bred to her brother 4A8 (this mating not shown 
in fig. 5) and her progeny of six born December 27, 1918, were 
allnormal. Lastly, she was mated again to 3A1, and on July 17, 
1919, brought forth seven young, the 10C series. One died im- 
mediately. Of the six remaining, five with normal eyes lived 
and one with both eyes defective died. 
To continue the history of the 4A series, 442, a normal-eyed | 
female, was first bred to 4A7 (eyes normal) and gave birth to 
five normal young on May 7, 1918. Then she was mated to 
4 A8 (eyes normal), and on December 11, 1918, produced five young 
which were likewise normal. After being bred to 4A7 on June 
3, 1919, she aborted one young. None of these matings are 
shown in the chart (fig. 5). 
Another normal-eyed female, 446, when mated to 3A1, had 
a litter of eight normal young on June 9, 1918. However, when 
she was mated to her brother 4A7, a normal-eyed male, one male, 
8B, from the litter of five born December 27, 1918, had the left 
eye normal in color and structure but small and a right eye with 
a translucent iris and cloudy lens (fig. 5). A female, 444, with 
a defective left eye also was mated to 3A1 and gave birth to eight 
normal young on June 10, 1918. Previously (April 4, 1918) she 
had also borne two normal-eyed young, although they had been 
fathered by 6A1, a male with both eyes defective. 
The defective-eyed offspring from the 4A series consists of 
eleven individuals: males 6A1, 10A4, 10A2, and 8B; females 
6A2, 6A3, 6A4, 6B, 10A1, and 10A3; 10C with sex undetermined. 
Passing now to the 4B series, one female, 4B1 (fig. 5) with the 
left eye collapsed was mated to 3A1 and produced four young on 
December 12, 1918. In one female, 27A, the right eye was 
exceedingly small, while the cornea and lens were both opaque. 
Only one of the 4E series had defective eyes and it died before 
it was old enough to leave progeny. Altogether, then, twelve 
defective-eyed rabbits were produced in the fourth generation; 
four males, one with sex undetermined, and seven females. In 
two females, four males, and the one in which the sex was unde- 
termined, both eyes were affected, while in two females the left 
eye was abnorml and in three females, the right eye. 
