220 
Biology of Pediculus humanus 
Date of emergence 
Total adults 
s 
$ 
%? 
Prior to following 
357 
167 
190 
53 
99 99 
149 
66 
83 
56 
21. x. 
210 
136 
74 
35 
22 
71 
44 
27 
* 
23 
31 
18 
13 
* 
28 
80 
46 
34 
* 
30 
54 
24 
30 
* 
Totals 
952 
501 
451 
47% 
* See footnote to previous table. 
CONCLUSION. 
In my previous paper ( loc. cit.) it was stated that of 208 adult capitis 
collected by me from a woman in Cambridge 50 % were female; of 100 
capitis raised by me 57 % were female, whilst of 944 corporis raised by 
Hindle roundly 60 % were female. (The first of these records is included in 
the table on p. 219.) 
Of 2769 adult corporis and capitis collected for me in different parts of the 
world 59 % were females. Of 952 corporis raised by me experimentally in 
Cambridge 47 % were females. 
It would appear from the tabulated figures that the proportion of the 
sexes varies, this depending on conditions which remain to be determined. 
SUMMARY. 
Refer to the conclusions stated at the end of the foregoing sections on 
pp. 204, 206, 217-219 and the foregoing paragraph. 
REFERENCES. 
See Bibliography in Parasitology, x. pp. 1-42, 582-58(5. 
Sikora, H. (ix. 1917). Zur Kleiderlaus-Kopflausfrage Vorlaufige Mitteilung. Arch. f. 
Sckijfs- u. Tropen-Hyg. xxi. 275-284, 3 figs. 
Corrections. 
Pp. 467, 468, 475, PI. X, figs. 1-2. The 11 Newman” Disinfector was designed and an illustrated 
description of it published by Dr John C. Thredi in 1902 (see The “Emergency” Disinfector, Brit. 
Med. Journ. i. pp. 1606-1608, figs. 1, 2). Dr Thresh informs me that the perusal of my paper (loc. 
cit. ) gave him the first intimation that his apparatus was being sold under the Trade name of the 
“Newman.” The vendors of the latter might with advantage give credit to the designer in the 
circulars dealing with this apparatus. 
P. 426, footnote. Read “Semon” in place of “Lemon.” The error is due to a misprint in the 
publication quoted. 
P. 581. “duddie” should be defined as meaning ■'ragged.” . 
EXPLANATION OF PLATE X. 
Pediculus humanus corporis. Specimens treated with caustic potash and mounted in balsam. 
Illustrating Experiment I (see text, pp. 209-210). 
Fig. 1. 3 and 7 $ (10 out of 40 raised) maintained in a black pill-box. All the insects were 
darkly pigmented. 
Fig. 2. 8 7 Q (15 out of 37 raised) maintained in a white pill box. Nearly all the insects are 
pale or but slightly pigmented. 
