SEX-LINKAGE IN FOWLS 511 
then is as follows. It is obvious that all the lugens moths used 
were heterozygous. 
Lug.o LM IM 
Tan 29) IM tim 
TL, eens 
IM IM — 
oO 
co 
LM Im — lug. 2 13 
2 
IM im — 
31 
tau 14 
tau 28 
The results of this one cross are not in accord with my hypoth- 
esis, since all four classes should be equal, but I think the num- 
bers are rather too small to be very significant. The reciprocal 
cross gives: 
Tau 0 IM- IM 
Gametes, lug. 9 2 LM21m 11M 1Lm 
21M LM —lug. 
11M IM —tau 
21M Im —tau 
11M Lm —lug. 
40 40 Qh Qy 
—_— 
ww 
This case comes out as I expect, but since the numbers are no 
larger and no more disproportionate than those in the first cross, 
I must rest my case on the third: 
Lug. & LM IM 
LM LM 
LM IM 
IM LM 
IM IM 
LM Lm 
IM Lm 
LM Im 
IM Im 
OO CO 
Gametes, lug. 9 2 LM1IM2 lm Lm 
J 
—§ lugo 129 
4 
—Itauco 16 
—4lug.9 94 
—2tau 9 36 
The relative size of the classes is perhaps as near the expected 
proportion as could be looked for, and becomes still nearer expec- 
tation if the coupling strength be increased slightly.» So much, 
then, for the experimental evidence bearing upon the case. 
5Standfuss (10) has published more data on this cross, but unfortunately has 
not reported the sex ratios obtained. 
THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 12, NO. 4 
