10 
ence 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 neglected. 
It is not known to infest other 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 preceding 
species, though the markings at the sides are less 
distinct. In the adult forms, however, the dorsal 
surface is marked with dark transverse bands. 
Fig. 4. Pediculus vesti- .,„.,,.,, 
menu (after Denny). The insect secretes itself in the folds of the cloth- . 
ing, only penetrating the skin when in want of food. 
The long, slender sucking tube, by means of which it reaches the small 
blood vessels near the surface, is shown fully extended in Fig. 1. 
The eggs are deposited in folds of the clothing, and, according to the 
estimates of Leeuwenhoek, a single adult female may have a progeny of 
5,000 in 8 weeks, and he adds that in the heat of summer this estimate 
might be very greatly exceeded. This will readily account for all the 
authentic accounts of sudden and numerous appearances of this pest. 
A ready means of combating this pest is to thoroughly bake the 
clothing infested with it, or, to be fully as effectual with less heat, this 
might be accompanied by fumigation with sulphur or tobacco smoke. 
A repetition of this process two or three times at intervals of a few days, 
along with strict personal cleanliness, should overcome the most serious 
attack. 
Alt describes, under the name of Pediculus tabescantium, the louse, 
which he considered as the cause of phthiriasis, but later authorities 
consider this as simply the vestimenti present in aggravated numbers. 
Properly speaking, this affection should be termed Pediculosis, and the 
term phthiriasis reserved for the attacks of Phthirius inguinalis. 
LOUSE OF THE APE. 
{Pediculus consobrinus Piaget.) 
Closely related to the human lice is a species described by Piaget 
occurring upon the Ateles ape (Ateles pentadactylus). It resembles es- 
pecially the Pediculus capitis, but presents some differences in form of 
head and structure of abdominal appendages which have led this author 
to establish the separate species. It appears to differ less, in general 
appearance, from typical capitis than the varieties of capitis occurring 
on different races differ among themselves. 
