LEPIDOPTEEA. 147 



with stinging bristles, which cause such smarting and itching to 

 our skin, and produce blisters upon it ? 



It has often been said that each plant has its own peculiar species 

 of caterpillar. All we can say is, that a certain number of veget- 

 ables only suit certain caterpillars. The species which eat roots 

 are few ; those which live in the interior of stalks or stems which 

 they feed on are numerous, and those which nourish themselves on 

 the pulp of fruits are rare. In general, after the leaves, the cater- 

 pillars prefer the flowers ; in this they certainly do not show bad 

 taste. Their growth is more or less rapid, according to the species, 

 according to the nourishment they take, and according to the season 

 of the year. Those whose food is succulent grow more rapidly than 

 those which have for their food dry gramineous plants and coria- 

 ceous lichens. Most of them eat at night, and remain during the 

 day motionless, and as it' were in a state of torpor ; others are so 

 voracious that they are constantly eating. This voracity is indeed 

 sometimes surprising. Malpighi has observed that a silkworm 

 often eats in a day a weight of mulberry leaves equal to its own 

 weight. How could we provide our horses and oxen with pro- 

 vender, if they required each day their own weight of hay and 

 grass? There are even some caterpillars which are still more 

 voracious than that. Reaumur weighed several caterpillars of a 

 species which lives on the cabbage, and gave them bits of cabbage 

 leaves which weighed twice as much as their bodies. In less than 

 twenty-four hours they had entirely consumed them. In this 

 space of time their weight increased one-tenth. Fancy a man 

 whose weight is 180 Ibs. eating in one day 360 Ibs. of meat, and 

 gaining 18 Ibs. in weight ! Caterpillars eat by the aid of two 

 jaws or mandibles, so broad and solid that, considering the 

 smallness of the insect, they are equivalent to all the teeth with 

 which large animals are furnished. It is by the alternate move- 

 ment of these mandibles that the caterpillars devour the leaves 

 with so much greediness and ease. 



" A caterpillar, when it wants to gnaw the edge of a leaf," says 

 Reaumur, " twists its body in such a way that at least one portion 

 of the edge of this leaf is passed between its legs. These legs hold 

 fast that portion of the leaf which is to be cut by the insect's 

 jaws (Fig. 101). To give the first bite, the caterpillar elongates 



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