270 
natural history. 
several bristly hairs : in the fore part is a proboscis or sucker, 
which is seldom visible : on each side of the head are anten- 
nae, or horns, each divided into five joints, covered with 
bristly hair ; and several white vessels are seen through 
these horns: behind these are the eyes, which seem to want 
those divisions observable in other insects, and appear en- 
compassed with some few hairs : the neck is very short, and 
the breast is divided into three parts : on each side of which 
are placed six legs, consisting of six joints covered also with 
bristly hairs: the ends of the legs are armed with two 
smaller and larger ruddy claws, serving those insects as a 
finger and thumb, by which they catch hold of such objects 
as they approach : the end of the body terminates in a 
cloven tail, while the sides are all over hairy ; the whole re- 
sembling clear parchment, and when roughly pressed, crack- 
ing with a noise. 
When we take a closer view, its white veins, and other in- 
ternal parts, appear ; as likewise a most wonderful motion 
in its intestines, from the transparency of its external cover- 
ing. When the louse feeds, the blood is seen to rush, like 
a torrent, into the stomach : and its greediness is so great, 
that the excrements contained in the intestines are ejected 
at the same time, to make room for this new supply. 
The louse has neither beak, teeth, nor any kind of mouth. 
In the place of all these, it has a proboscis or trunk ; or, as 
it may be otherwise called, a pointed hollow sucker, with 
which it pierces the skin, and sucks the human blood, taking 
that for food only. The stomach is lodged partly in the 
breast and back ; but the greatest portion of it is in the ab- 
domen. When it is empty, it is colourless ; but when filled, 
it is plainly discernible, and its motion seems very extraor- 
dinary. It then appears working with very strong agita- 
tions, and somewhat resembles an animal within an animal. 
Superficial observers are apt to take this for the pulsation 
of the heart; but if the animal be observed when it is suck- 
ing, it will be found that the food takes a direct passage 
from the trunk to the stomach, where the remainder of the 
old aliment will be seen mixing with the new, and ao-itated 
up and down on every side. 
If this animal be kept from food two or three days, and 
then placed upon the back of the hand, or any soft part of 
the body, it will immediately seek for food ; which it will 
the more readily find, if the hand be rubbed till it grows red. 
The animal then turns its head, which lies between the two 
fore legs, to the skin, and diligently searches for some pore : 
when found, it fixes the trunk therein : and soon the 
