HEMIPTERA. 167 
from the head, and are most abundant, we have observed, back of the 
ears. When numerous they form quite conspicuous objects. The 
young, upon hatching from these, resemble the adults, except in size 
and in being less distinctly marked. The proportions of 
the body are also somewhat different, the abdomen being 
smaller than after it has become enlarged by a steady 
diet upon human blood. The full-grown lice are whitish, 
with faint, dark markings at the sides of the thorax and 
abdomen. The last segment of the abdomen in the 
female is bilobed. 
Murray has shown that the different races of man har- 
bor different varieties of this species of louse, the differ- | 
ence in the varieties being particularly in color and in the Fie. 96.—Pedicutus 
form of the claws. In color they differ from the nearly cae 
white infesting the Caucasians to the black infesting the 
African. The claws differ somewhat in proportions, and Murray thinks 
these differences constant, but they can at most be considered only as 
varietal differences. 
Remedies are white precipitate, sulphur ointment, and especially 
cleanliness. 
THE Boby LOUSE. 
(Pediculus vestimenti Leach.) 
As with the preceding species, the history of this parasite is lost 
in antiquity, and most of the early accounts failed to indicate any dif- 
ference in the two forms. In the works of DeGeer, Leach, Denny, and 
others they are distinguished and well characterized. 
This form is most common where opportunities for good sanitation 
are wanting, as in armies, prisons, and all places where attention to 
bodily cleanliness from choice or necessity is neg- 
lected. 
It is not known to infest animals, though we 
have seen specimens that were said to have been 
taken from cattle. 
Until fully grown there is not much difference 
to be noted in the appearance of this and the pre- 
ceding species, though the markings at the sides 
are less distinct. In the adult form, however, the 
dorsal surface is marked with dark transverse 
bands. 
The insect secretes itself in the folds of the 
Fig. 97—Pediculus vesti- clothing, only penetrating the skin «hen in want 
menti (after Denny). 
of food. The long, slender suching tube, by 
means of which it reaches the small blood vessels near the surface, is 
shown fully extended in figure 94. 
