23O INSECTS. 



happen to be dead. The relative proportions of the 

 feet determine, in a certain degree, the manner of 

 each insect*s motion in walking. Those species 

 that have long legs (generally speaking) run very 

 quickly, as the Spiders, the Long-legged Spiders, 

 and several kinds of Beetles. On the contray, the 

 insects that have short legs, as the Julus, licks, 

 and Gall Insects, are generally remarkable for the 

 slowness of their pace. When the anterior feet are 

 the longest, they relard the motion: this takes 

 place in the Ephemera, Mantis, and some others : 

 the feet of these insects are of little other use to 

 them than in enabling them to lay hold of any- 

 body on which they wish to alight. The posterior 

 legs, being longest, give to the insects the faculty of 

 leaping. Some insects however leap, whose poste- 

 rior legs are not longer than the others; but they have 

 this iaculty in consequence of the thighs being very 

 thick, and furnished with particular muscles. 



The tongue of insects is a taper and compact instru* 

 ment, by which they suck their food. Some of the 

 animals can contract or expand it ; and others, as 

 the Butterflies, roll it up under their head, somewhat 

 like the spring of a watch. In many it is enclosed 

 within a sheath ; and in several, as the flies, it is 

 fleshy and tubular. 



The mouth is generally placed somewhat under- 

 neath the front part of the head ; but in a few of 

 the tribes it is situated below the breast. Some 

 insects have it furnished with a kind of forceps, for; 

 the purpose of seizing and cutting their prey ; and 

 in others it is pointed, to pierce animal or veget- 



