192 
GENETIC STUDIES ON THE SILKWORM 
Melanism. n (Melanie, B, v. chocolate, b.) 
In the presence of B, the pigment colour of the patterns is melanic, as 
is the case with ordinary strains, while in its absence the markings are 
chocolate [cf. p. 1 32). 
a) Behaviour of B towards 0, K, and Q, has not been tested yet. 
b) B and P, B and Y- 
Heterozygous 3-moulting melanic normal yellows (PpäQBbTtYy) 
mated inter sc. 
735''5 
3"'"- (T) 
4-m. (t) 
Totals 
Mel. norm. yel. 
PQBY 
21 
49 
70 
Mel. norm. wh. 
PQBy 
6 
M 
20 
Mel. qu. yel. 
pQBY 
7 
13 
20 
Mel. qu. wh. 
pQBy 
6 
9 
'5 
Choc. norm. yel. 
PQbY 
4 
6 
10 
Choc. norm. wh. 
POby 
1 
2 
3 
Choc. qu. yel. 
pQbY 
3 
3 
6 
Choc. qu. wh. 
pQby 
I 
r 
2 
Totals 
49 
97 
146 
Of which 
PB 90 
: Pb 13 
: PB 35 = 
pb 8 
BY 90 
: By 35 
: bY 16 : 
by 5 
Exp. ratio 
9 
: 3 
: 3 
1 
c) B and L. 
Heterozygous melanic striped-multi lunar yellows (SsPPQqLlBbYy) 
mated inter sc. 
A ;59'i 5 Melanic (B) Chocol. (b) 
Str. multil. yel. SPQLY 16 10 
Str. multil. wh. SPQLy 2 1 
Multil. yel. sPqLY 5 I 
Multil. wh. sPqLy 6 1 
Totals 
26 
3 
6 
7 
1) That the chocolate character mendelizes as a simple recessive to the melanic was first made 
out l>y Toyama (1909). 
