





























| ti 148 THI; LNSECT WORLD. 
) its body, and carries its head as far forward as possible. The por- 
| tion of the leaf which is between the open jaws is cut through the 
Hid . _... instant the teeth meet each 
SSN y other; the bites succeed each 
other quickly; there is not 
one of these, or scarcely one 
of them, that does not detach 
a bit, and each bit is swal- 
lowed almost as soon as cut 
off. At each fresh bite, the 
head draws near to the legs; 
in such a way that during the 
remaining bites it describes an 
are ; it hollows out the portion 
of the leaf in a segment of a 
circle, and it is always in this order that it gnaws it.” 
But there is a phenomenon in the life of caterpillars which we 
ought to point out, and which has attracted the attention of the 
most illustrious observers. All caterpillars change their skins 
a many times during their life. It is not indeed enough to say 
that they change their skins; the skins or cases they cast are so 
complete, that they might be taken for entire caterpillars. The 
Ve hairs, the cases of the legs, the nails with which the legs are 
provided, the hard and solid parts which cover the head, the 
teeth,—all these are found in the skin which the insect abandons. 
What an operation for the poor little animal! This work is so 
enormous, so troublesome, that one cannot form a just idea of it. 
One or two days before this grand crisis, the caterpillar leaves 
off eating, loses its usual activity, and becomes motionless and 
languid. Their colour fades, their skin dries little by little, they 
bow their backs, swell out their segments. At last this dried-up 
skin splits below the back, on the second or third ring, and lets 
us have a glimpse of a small portion of the new skin, easily to be 
recognised by the freshness and brightness of its colours. : 
““When once the split has been begun,” says Réaumur, “it is 
easy for the insect to extend it; it continues to swell out that part 
of its body which is opposite the slit. Very soon this part raises 
itself above the sides of the split; it does the work of a wedge, 

Fig. 101.—Looper Caterpillar eating the leaves 
: of the Apricot (after Réaumur. ) 

oN 

