152 PHYSOPODA. 



energy than the preceding, and have a much longer-sustained 

 flight. The powers of devastation possessed by the Locusts are 

 almost inconceivable ; for they are produced in vast numbers, 

 and live in societies, so as speedily to destroy the vegetation of 

 the spot on which they have settled. Thence they take their 

 flight in vast multitudes to adjoining districts ; and so great is 

 the number of which these swarms consist, that it is not speaking 

 figuratively to say that the sky is darkened by their passage. 

 Their ravages usually continue until they are checked for want 

 of a further supply of food ; for as the instinct of the Locusts 

 leads them to continue their flight in the same direction, they 

 are at last stopped either by the desert or the sea ; and some- 

 times a storm, carrying them out of their course, or hurrying 

 them on in it, effects a clearance much more speedily than any 

 other cause could do. Of the cause of the occasional appearance 

 of the Locusts, in such vast multitudes, no satisfactory explana- 

 tion has been given. Of these Insects there are several different 

 species, which are distributed over the tropical and the warmer 

 temperate regions of the globe ; and in many parts they are used 

 as food by the inhabitants of the countries they infest. 



ORDER III. PHYSOPODA. 



733. The small order of the PHYSOPODA includes some 

 minute insects which were placed with the Rhynchota byLinnasus 

 and the older Entomologists, in consequence of their mouths 

 being drawn out very much in the form of a rostrum. They 

 are, however, more nearly allied to the Orthoptera, although 

 they are at once distinguished from those insects by the weak- 

 ness of the organs of the mouth. As in the Orthoptera, the 

 metamorphosis is incomplete. The wings, which are usually four 

 in number, are flat and generally very narrow, but fringed, 

 sometimes all round, sometimes only at the apex, with long 

 delicate hairs. The antennas generally consist of about eight 

 joints, and are situated on the front of the head between the 



