OF INSECTS IN GENERAL. 118 



Eyes, raourh, proboscis, jaws, tongue. 



form in their turn some office, perhaps that of 

 smell. 



Many insects have no tongue, nor make any 

 sound with their mouth; but, for this purpose, 

 some use their feet, others their wings, and others 

 some elastic instrument with which they are na- 

 turally furnished. 



Most insects have two eyes, but th,e gyrinus 

 has four, the scorpion six, the spider eight, and 

 the scolopendra three ; they have no eye-brows, 

 but the external tunic of their eyes is hard and 

 transparent like a watch-glass ; their eyes have 

 no external motion. They chiefly consist of one 

 lens only; but in those of the butterfly, and many 

 of the bettles, they are more numerous. Pugett 

 discovered 17,325 lenses in the cornea of a but- 

 terfly, and Leuwenhoek 800 in a fly. 



The mouth of most insects is placed in the 

 anterior part of the head, extending somewhat 

 downward; but in some it is placed under the 

 breast, as in the chermes, Sec. Many have a 

 proboscis, which is the mouth drawn out to a 

 rigid point; in several of the hemiptera class it 

 is bent downward towards the breast and belly, 

 as in the bug, &c. They have in general two 

 jaws; some of them, indeed, have four, and 

 others even more; they are placed horizontally; 

 the inner edge of them in some is serrated, or 

 furnished with little teeth. The tongue, as in 

 the butterfly, is taper and spiral, but in others it. 



VOL. VI. NO. 41. P 



