66 SUPPLEMENT ON 



can absorb or suck their aliment in a liquid form, and, con- 

 sequently, without mastication ; while, under other circum- 

 stances, the parts of their mouth having changed form, they 

 will attack nothing but solids. This is not the place to quote 

 numerous examples of such modifications ; sufficient will be 

 exhibited in the course of this work ; but we must mention a 

 few of the more remarkable. 



The hydrophili, which in their first state the French call 

 vers assassins, which attack and suck the tadpoles of reptiles, 

 small fish, moUusca, and which, in their final form, feed 

 only on aquatic plants, and the half-decomposed leaves of 

 vegetables which fall into the water, furnish us with a clear 

 example of a zoophagus animal becoming phytophagus. It 

 is the same with the anthreni, the telephori, &c. On the 

 other hand, the larvae of the antlion suck their prey without 

 masticating it, and the perfect insect has a mouth perfectly 

 organized for bruising its aliments. In opposition to this, 

 we find the caterpillars of lepidoptera, as, for instance, the 

 silkworm, gnaw and chew the leaves, while butterflies, 

 bombyces, &c. can only suck the nectar of the flowers with 

 their spiral tongue. These differences of habits and confor- 

 mation in the parts of the mouth are always connected with 

 important modifications in the other digestive organs. 



Each insect knows perfectly well the aliments which are 

 proper for the ureservation of its life, and for the growth 

 of its body. It knows how to seek and procure them. 

 There are many, indeed the greater number, which have no 

 occasion to seek their food at any distance. All insects are 

 endowed with an instinct which leads them to deposit their 

 eggs, or the germs of their progeny, where they can easily 

 procure nourishment, or to provide for their subsistence. 

 Notwithstanding the change of food, which we have just 

 remarked, yet insects in the perfect state, notwithstanding 

 that they live so differently from their larvae, know perfectly 



