148 THE INSECT WOBLD. 



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 



instant the teeth meet each 

 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 



Fig. 101,-Looper Caterpill^Tating the leaves arc 5 {i ^olloWS Out the portion 

 of the Apricot (after Reaumur.) of ^ leftf ^ ft gegment Q f 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 

 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 

 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 Reaumur, " 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, 



