116 
Biology of Pediculus hum anus 
Table showing the Disparity of the Sexes. 
(a) In the offspring of 25 isolated pairs (Hindle). 
rrporis 
Progeny raised 
Corporis 
Progeny raised 
pair 
(? 
$ 
paii- 
a 
9 
1 
9 
0 
14 
0 
9 
2 
12 
0 
15 
13 
18 
3 
10 
5 
16 
0 
2 
4 
26 
0 
17 
28 
2? 
5 
0 
4 
18 
2 
9 
6 
0 
36 
19 
38 
0 
7 
17 
8 
20 
0 
6 
8 
14 
3 
21 
0 
24 
9 
0 
34 
22 
0 
64 
10 
0 
48 
23 
2? 
27 
11 
27 
0 
24 
8 
2 
12 
0 
45 
25 
0 
26 
13 
1? 
31 
— 
— 
Totals 
206 
383 
( b) In the offspring of mixed pairs (selected examples from Hindle). 
Parents 
Progeny raised 
a ? 
a 
? 
13 + 15 
13 
15 
6+ 4 
54 
0 
6+ 4 
28 
0 
6+ 4 
0 
42 
6+ 8 
12 
8 
8+ 4 
0 
32 
10+ 4 
0 
37 
On the other hand, the following protocol from my own experi¬ 
ments shows greater uniformity in the proportions of the sexes (raised 
at 31° C.): 
Progeny 
Total adults raised 
Parents 
raised 
from 1st stage 
a ? 
a 
9 
larvae 
2 4 
25 
13 
37% 
4 4 
17 
12 
34% 
3 5 
16 
14 
35% 
4 4 
8 
16 
38% 
13 17 
66 
55 
Average 36% 
Bacot’s observations relate to hybrids of (a) capitis + corporis $ 
and ( b ) corporis q + capitis $, the progeny of fewer pairs having been 
reared than in Hindle’s experiments but the respective broods being 
