70 



troublesome effects when applied to the human 

 skin ; and the deadly venom of the rattle-snake, 

 or cobra-da-capello, is collected arid introduced 

 into a wound in a similar manner. In the cray- 

 fish, and insects in general, the place of a tongue 

 is supplied by the tentacula which surround the 

 mouth, what is commonly called their tongue, be- 

 ing only, as I have before remarked, a prolonga- 

 tion of the lower lip. In those insects, however, 

 the lips of which are prolonged in the form of a 

 proboscis, the tongue is a kind of sucking tube, 

 contained within it ; while in the bee, the tongue 

 is rolled into a sucking cylinder, within the 

 elongated jaws. The structure of the jaws is in 

 some insects very perfect, particularly in the cray- 

 fish, in which they are divided into two mandi- 

 bles, analogous to grinding teeth, and six pairs of 

 proper jaws, moving from side to side, and not 

 upwards and downwards, as in most other ani- 

 mals. Similar, in this respect, to the cray-fish is 

 the scorpion and the spider ; while the beetle is 

 intermediate, as it were, between these and the 

 more perfect insects, which feed chiefly on juices, 

 and take their food by suction. The larvae of 

 insects in general, however, or these animals in 

 their rudimental state, are commonly furnished 

 with very powerful jaws. 



Of the vertebral animals, the lips of some 

 fishes, as the sturgeon and the lamprey, are very 

 similar to those of some worms ; and their suck- 

 ing power is so great, that the lamprey may be 



