The remedies adopted for the head louse are applicable to this spe- 
cies, though it is said they are less effectual and must be persisted in 
more vigorously. Red precipitate is probably most frequently used. 
THE HEAD LOUSE. 
(Pediculus capitis De Geer.) 
This louse has been recognized under one name or another as far back 
as we have history. While very generally confused with the following 
species it is probably the one most commonly known, though perhaps not 
the one which has caused the greatest amount of annoyance or that has 
occurred in the greatest numbers. The two species were not clearly 
defined till comparatively recent times. 
Elaborate writings upon the louse were given by Swammerdam, Leeu- 
wenhoek (1693), and descriptions of it by Redi, DeGeer, 
Linne, Geoffroy, Burmeister, Leach, and others, besides in- 
numerable brief mentions and a goodly number of elabor- 
ate memoirs upon its embryology, etc. In later days, while 
a most annoying pest, it does not appear to have caused 
such serious results as the body louse or the crab louse. 
It is confined to the fine hair of the head, rarely occur- 
ring on other parts of the body. 
The eggs (nits) are white and glued to the hair at some 
distance from the head, and are most abundant, we have fig.3.— Pediculus 
observed, back of the ears. When numerous they form ca P ;tig ,after 
quite conspicuous objects. The young upon hatching 
from these resemble the adults, except in size and in being less dis- 
tinctly marked. The proportions of the body are also somewhat differ- 
ent, 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 harbor different 
varieties of this species of louse, the difference in the varieties being par- 
ticularly in color and in the form of the claws. In color they differ from 
the nearly white infesting Europeans 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 BODY 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 differ- 
