THE BODY-LOUSE OF MAN. 99 
are attached to the clothing, especially along the seams 
where these come in contact with the human body. From 
about 60 to 70 eggs are deposited by each female. During 
the warmer part of the year these lice can increase very 
rapidly in numbers, and Leeuwenhoek has estimated that a 
single adult female could have in eight weeks a progeny of 
5000. This rapid increase accounts for the many authentic 
accounts of their sudden appearance. A disease, mentioned 
by the very earliest writers, the PAthiriasis, was stated to 
be caused by lice and it seems probable that this is the spe- 
cies referred to. These parasites prefer the less hairy parts of 
the body, as the neck, back, 
and abdomen, where they can 
cause a sort of eruption; or 
they simply redden the skin in 
larger or smaller spots, which, 
on account of the constant 
scratching induced by theitch- 
ing presence of the insect, 
become sores. Fig. 67 shows 
this nasty parasite. 
Incases in which thecloth- 
ing is seldom changed, as is 
usually the case in armies dur- 
ing war, these insects, fre- 
weg. StgPosylouse of man. Great quently called “Grey-backs,” 
increase very rapidly in num- 
bers and become a great source of annoyance. Many, if not 
most of our veterans can tell wonderful stories about these 
parasites; in fact some yarns have been told about them 
that require a very strong constitution to stand the strain 
in believing them. These lice become also very numerous in 
lumber-camps and other places where bathing and a fre- 
quent change of clothing are out of the question. Persons 
forced to live for a long time in camps can only protect 
themselves against these unpleasant intruders by cleanli- 
ness, and by changing their underwear as frequently as pos- 
sible. The parasites in soiled clothing are readily killed by 
boiling or baking it. 

