INSECTS. 229 
tle air; and when they go to sleep for the winter they 
require none, and their breathing stops. 
392. Some insects live on the juices of plants and of 
animals, and some devour the substance of either the 
one or the other. The former suck their food; the lat- 
ter gnaw it. These two classes, therefore, have two dif- 
ferent kinds of mouths. The gnawers, such as Beetles, 
Cockroaches, Locusts, etc., have a complicated apparatus, 
which I will describe. First, there are two tooth or 
claw-like appendages, called mandibles; these are the 
upper jaws, which divide the food. They come together 
by a lateral or sidewise motion. Sometimes they have 
sharp edges to cut like sciasors, and sometimes they have 
points for tearing. Below or behind these are two other 
jaws, called mazxille, which are very complex in their 
structure. Above, or, rather, in front of the mandibles, 
is a lip, and so there is one behind the maxille. Insects 
furnished with an apparatus of this kind are called man- 
dibulate. 
393. In some insects we have an arrangement entirely 
of a different character, as in the Butterfly tribe. Here 
there is a tubular appendage, or trunk, often quite long. 
This is ordinarily coiled up, as you see 
Re in Fig.179. When the animal wishes, 
a it can uncoil it and extend it down 
@ into the bosom of flowers. Such in- 
sects are called Haustellate, from 
haustellum, a sucker. This tube, or 
Beale. proboscis, varies much in different in- 
sects. In some, as the Bees, there is a mixture of the 
mandibulate and the haustellate arrangements. They 
obtain their food by suction, and use their mandibles 
and maxille as trowels and spades, and knives and scis- 
sors, in building their curious habitations. In insects 
that suck the blood of animals, such as the Musquito 
and the Horsefly, there is a peculiar modification of the 
apparatus. There is a proboscis with lancets to make 
