TRANSMISSION OF INDUCED EYE-DEFECTS 207. 
Offspring from the fourth generation are chiefly from matings 
between the 10A and 6A series, hence each series cannot be con- 
sidered separately. The female 6A2 in which both eyes were 
defective was mated to 10A4 (both eyes abnormal), and on April 
5, 1919, bore seven young, all of which died between July 20 and 
July 28, 1919. However, four of the lot had eye defects (fig. 5). 
One female had a bad left eye and two males and one female had 
both eyes defective. Of the males one never opened his eyes, 
but a postmortem held after his death on May 7th revealed small 
eyeballs under the shut lids. <A female, 6A3, with an abnormal 
right eye was bred to 6A1, a male with both eyes defective, and 
the three individuals born May 31st were all normal (not shown 
in the chart). Another female, 6A4, (fig. 5) with the left eye 
affected was first bred to 10A2, a male with both eyes defective. 
Of the four young born January 22, 1919, one male 28A3 had a 
small right eye in which the lens was milky. Another male 28A4 
had a left eye normal in size, iris and color, but the lens was 
clouded; the right eye was one-third normal size, had a cleft iris, 
cloudy lens, and persistent hyaloid artery. A female, 28A2, was 
normal-eyed in appearance, although one lens had a streak across 
Hi 
The male, 28A3, was mated to his mother (6A4, left eye de- 
fective) and one, 28B, of the two young born July 8, 1919, had a 
collapsed eyeball on the left side with only a slight indication of 
iris and pupil; the right eye was small and the lens contained 
opaque spots (fig. 5). A female, 10A3, with both eyes abnormal 
after being mated to 10A4, similarly affected, brought forth 
four young, the 40A series, May 31, 1919. Two of these had 
normal eyes; one female had a right eye affected and one male 
had both eyes affected (fig. 5). 
When bred to 28A4, (pl. 4) 10A1 (left eye defective) gave birth 
to seven young on October 26, 1919. These, known as the 45A 
series (fig. 5), contained five with bad eyes, as follows: a female 
with left eye normal in size and general appearance, but with 
an opaque lens; a female with a partially opaque lens and colo- 
boma in the right eye; a female with a smaller left eye in which 
the iris was incomplete and the lens opaque; a male with both 
