86 
Parasitic Arthropods 
and are provided with powerful claws fitted for clinging to hairs. 
The females (fig. 69) measure 1.5 to 2 mm. in length by 1.5 mm. in 
breadth. The male averages a 
little over half as large. The eggs, 
or nits, are fixed at the base of the 
hairs. Only a few, ten to fifteen 
are deposited by a single female, 
and they hatch in about a week’s 
time. The young lice mature in 
two weeks. 
The pubic louse usually infests 
the hairs of the pubis and the 
perineal region. It may pass to 
the arm pits or even to the beard 
or moustache. Rarely, it occurs 
on the eyelids, and it has even 
been found, in a very few instances, 
occurring in all stages, on the scalp. 
Infestation may be contracted 
from beds or even from badly in¬ 
fested persons in a crowd. We 
have seen several cases which un¬ 
doubtedly were due to the use of 
public water closets. It produces 
papular eruption and an intense 
pruritis. When abundant, there 
occurs a grayish discoloration of 
the skin which Duguet has shown 
is due to a poisonous saliva injected by the louse, 
as is the melanoderma caused by the body louse. 
The pubic louse may be exterminated by the <5 ~' ~~~ 
measures recommended for the head louse, or / /// 
by the use of officinal mercurial ointment. 
68. Melanoderma caused by the body 
louse. From Portfolio of Dermo- 
chromes. by permission of Rebman 
& Co., New York, Publishers. 
IIemiptera 
Several species of Hemiptera-Heteroptera are 69 Phthirius pubi ,. Ven _ 
habitual parasites of man, and others occur jv'iof pect of ^ emalc - 
as occasional or accidental parasites. Of all 
these, the most important and widespread are the bed-bugs, belong¬ 
ing to the genus Cimex (= Acanthia). 
