36 BOARD OF AGRICULTURE. 
very low, degraded Hemiptera, destitute of wings. ‘The head 
is small, conical, and narrow; the thorax is small and in- 
distinctly separated into segments ; the 
abdomen is large,. flattish, rounded or 
oval, with nine segments. The antenne 
are very slender and five-jointed. The 
eyes are simple and very minute. The 
feet, or tarsi, have two joints, the 
last joint forming a strong hook for 
grasping the hairs firmly while crawling 
and climbing among it. The mouth- 
parts form a long and extremely slender 
fleshy tube, which is retracted when not 
in use, and is capable of being intro- 
duced into the skin, for the purpose of 
sucking blood. The structure of the 
mouth is as follows, according to 
Schiddte: ‘‘ The peculiar attenuation of 
the head in front of. the antenne at once 
. suggests to the practised eye the exist- 
ence of a mouth adapted for suction. 
This mouth differs from that of Rhyn- 
chota [Hemiptera, bed-bug, etc.] gen-. 
erally, in the circumstance that the 
labium is capable of being retracted into 
the upper part of the head; which there- 
fore presents a little fold, which is ex- 
tended when the labium is protruded. 
In order to strengthen this part, a flat 
band of chitine is placed on the under 
surface, just-as the shoemaker puts a 
Figure 29. 
Figure 29.—Proboscis of body-louse (Pediculus corporis DeGéer), entirely pro- 
truded and seen from above, magnified one hundred and sixty times ; ant the 
summit of the head, with four bristles on each side; bb, the chitinous band, and 
c, the hind part of the lower lip—such as they appear through the skin by sie a 
transmitted light; dd, the foremost protruding part of the lewer lip (the _haus- 
tellum) ; ce, the hooks turned outwards; f£ the inner tube of suction slightly 
bent and twisted; the two pairs of jaws are perceived on the ihe aa th 
lines ; a few blood globules are seen in the interior of the tube.—From American 
Naturalist. Digitized by Microsoft® 
