92 



THE VITAL FUNCTIONS. 



mon grasshopper, arc delineated in llieir relative situations^ 

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

 jaws, {m,) which are termed the mandibles, are those prin- 



cipally employed for the mastication of hard substances; 

 they are, accordingly, of greater strength than the lower 

 jaws, and thcii- 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 the substances to 

 which they arc 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, w'hich 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 



clbarla; and upon their varieties of structure he founded his cclcbnitcd sys- 

 tem of entomological classification. Kirby and Spence have denominated 

 them iropfiL Sec their introduction to Entomology, vol. iii. p. 417. To 

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

 eighth, whicli he terms the Epv^lotasu. 

 * Knoch, quoted by Kirby. 



