CH. XV.^ THE CATERPILLAR. 255 



into a point, and which easily open in order to make 

 way for the extremity of the insect. 



When beginning to fabricate this mantle, the 

 caterpillar glides into the pulpy substance of a green 

 leaf, penetrates between the two membranes which 

 form its external coats, and detaches the pulpy sub- 

 stance or parenchyma, which is enclosed in these 

 membranes. This substance constitutes the proper 

 food of the caterpillar ; hence, while the animal satis- 

 fies the cravings of hunger, it prepares the stuff 

 from which its mantle is to be fabricated ; the two 

 membranes of the leaf are the stuff destined for this 

 purpose. Each of these thin substances is to the 

 caterpillar what a piece of cloth is to a tailor ; like 

 that useful mechanic, the little animal cuts each 

 piece of the form and proportion which it ought to 

 have, in order to answer the purpose for which it is 

 destined. 



Anxious to ascertain how this mantle was made, 

 Reaumur watched his opportunity, and removed one 

 of them, before the insect, which happened to be 

 then busily feeding in the parenchyma of the leaf, 

 had time to retreat : the creature, having discovered 

 its loss, seemed to be in great alarm, and came out 

 tail foremost; it felt about for its mantle, but not 

 finding what it sought, it re-entered between the 

 membranes of the leaf, where it began to feed right 

 and left ; having consumed the parenchyma, from a 

 space of adequate dimensions, it proceeded to repair 

 its loss. From the membranes of the leaf it cut 

 two pieces, equal in extent, and similar in shape, 

 each piece being destined to form one-half of the 

 mantle. This part of the process was executed 

 with singular rapidity, as well as with matchless 

 skill and precision. This is far from being a me- 

 chanical operation; for the pieces composing the 

 mantle are not regular figures, one end of each being 

 double the size of the other. The materials of the 



