GENETIC STUDIES ON THE SILKWORM 
Moulting Character. n (Three-moulting, T, versus four-moulting, t. ) 
There are a host of data which speak for the independent inheritance of 
moulting character ; a few typical cases are given below. 
a) T and Y, T and P. 
Heterozygous 3-moulting plain yellows (PpqqTtYy) mated inter sc. 
A 7 8 5 'i 5 A 7 86'i 5 
3-m. (T) 4-m. (t) Totals 3-m. (T) 4-m. (t) Totals 
PI. yel. PqY 84 27 111 103 42 145 
PI. wh. Pqy 28 10 38 40 18 58 
Pal. qu. yel.pqY 26 7 33 33 6 44 
Pal. qu. wh. pqy 10 6 16 15 2 17 
Totals 148 50 198 196 68 264 
Of which 
Expected ratio 
A heterozygous 3-moulting plain yellow (PpqqTtYy) % x a 4-moult- 
ing normal white (PPQQttyy) % ■ 
Yl 
Yt 
yT 
yt 
251 
82 
'J 3 
36 
9 : 
• 3 
• 3 
: 1 
pr 
Pt 
PT 
Pt 
2 55 
97 
89 
2 I 
A 789' 1 5 Norm. yel. PQY 
Norm. wh. POy 
T 
t 
Totals 
1 10 
108 
218 
1 12 
104 
216 
2 1 2 
434 
64 
•47 
92 
93 
185 
156 
176 
332 
i : 
1 
Totals 
Reciprocal to the above cross: 
A79C/15 Norm. yel. PQY 
Norm. wh. PQy 
Totals 
Ratio 
1) The moulting character is, on one hand, seriously affected by external circumstances, and, on 
the other hand, there is some indication that more than one allelomorphs are concerned in the charac- 
ter, lioth causes act to bring about divergent zygotic ratios which are often met with in inheritance 
of this character. But in the present section, I shall deal with only those cases in which simple 
Mendelian ratio was realised, (c/. Chapter VI.) 
