MOTIONS OF INSECTS. 361 



every pool thus working their little legs with great rapi- 

 dity, and moving about in all directions. — Some spiders 

 also will not only traverse the surface of the waters, but, 

 as you have heard with respect to one*, descend into 

 their bosom. There are other insects moving in this 

 way that are not divers. Of this kind are the aquatic 

 bugs {Gerris lacustris, Hydrometra Stagnorum, Velia 

 Rivulorum, &c. Latr.). The first can walk, run, and 

 even leap, which it does upon its prey, as well as swim 

 upon the surface. The second, remarkable for its ex- 

 treme slenderness, and for its prominent hemispherical 

 eyes — which, though they are really in the head, appear 

 to be in the middle of the body — rambles about in chase 

 of other insects, in considerable numbers, in most stag- 

 nant waters. The Velia is to be met with chiefly in run- 

 ning streams and rivers, coursing very rapidly over their 

 waves ^. The two last species neither jump nor swim. 



I am next to say a few words upon the motions of in- 

 sects that burroiv, either to conceal themselves or their 

 young. Though burrowing is not always a locomotion, 

 I shall consider it under this head, to preserve the unity 

 of the subject. Many enter the earth by means of fore- 

 legs particularly formed for the purpose. The flat den- 

 tated anterior shanks, with slender feet, that distinguish 

 the chafei's {Petalocera) — most of which in their first 

 states live under ground, and many occasionally in 

 their last — enable them to make their way either into the 

 earth or out of it. Two other genera of beetles (Sca- 

 rites and Clivinaf Latr. )*= have these shanks pahnated, 

 or ^armed with longer teeth at their extremity, for the 



^ Vor,. I. 470—. ^ Curtis Brit. Enl. I. ii. 



" Plate XV. Fig. 5. 



