Packard.] RELATIONS OE INSECTS TO MAN. 
69 
When looking about for a weak place in the skin of his 
host the creature alights upon a sweat pore. Into this he 
plunges his sucker, and anchors it there Fig. 55. 
by a number of hooks (Fig. 55, ee). 
After they have firmly grasped the 
surrounding flesh the first pair of bris¬ 
tles (the real mandibles transformed) 
are protruded (we are quoting Prof. 
Schiodte here almost word for word, as 
given in the “American Naturalist,” 
vol. iv, p. 86). These bristles are 
towards their points united by a mem¬ 
brane so as to form a closed tube. 
When the whole instrument is exserted, 
we perceive a long, membranous, flex¬ 
ible tube (the portion from e-f and 
including the end) hanging down from 
the under lip (labium), and along the 
walls of this tube the bristle-like jaws 
in the form of narrow bands of chitine. 
In this way, says Schiodte, the suck¬ 
ing tube can be made longer or shorter 
as required, and easily adjusted to the 
thickness of the skin in the particular 
place where the animal is sucking, 
whereby access to the capillary system 
is secured at any part of the body. 
“It is apparent from the whole struc¬ 
ture of the instrument, that it is by no 
means calculated for being used as a 
sting, but is rather to be compared to 
a delicate elastic probe, in the use 
of which the terminal lobes probably 
serve as feelers. As soon as the capillary system is reached, 
the blood will at once ascend into the narrow tube, after 
5 
Mouth of a Louse, 
