92 



THE VITAL FUNCTIONS. 



mon grasshopper, are delineated in their relative situatioflg> 

 but detached from one another, in Fig. 267. The upper 

 jaws, (M,) which are termed the mandibles, are those prin- 



267 



cipally employed for the mastication of hard substances; 

 they are, accordingly, of greater strength than the lower 

 jaws, and their edges are generally deeply serrated, so as to 

 act like teeth in dividing and Bruising the food. Some of 

 these teeth are pointed, others wedge-shaped, and others 

 broad, like grinders; their form being, in each particular 

 case, adapted to the mechanical texture of th^ substances to 

 which they are designed to be applied. Thus, the mandi- 

 bles of some Melolonthx have a projection, rendered rough 

 by numerous deep transverse furrows, converting it into a 

 file for wearing down the dry leaves, which are their natural 

 food.* In most cases, indeed, we are, in like manner, ena- 

 bled, from a simple inspection of the shape of the teeth, to 



cibaria,; and upon their varieties of structure he founded his celebrated sys- 

 tem of entomological classification. Kirby and Spence have denominated 

 them iropld. See their introduction to Entomology, vol. iii. p. 417. To 

 the seven elements above enumerated, Savigny adds, in the Hemipiera, an 

 eighth, which he terms the Epiglossa. 

 * Knoch, quoted by Kirby. 



