224 INSECTS. 



divided into segments or rings, which are capable 

 of being moved towards each other by muscular 

 bands situated within the body. The motions of 

 many of the larva? are performed on these rings only, 

 either in the manner of serpents, or by resting alter- 

 nately each segment of the body on the plane which 

 supports it. Such is the motion of the larvae of the 

 Flies, emphatically so called, and of the wasps and 

 bees. Sometimes the surfaces of the rings are co- 

 vered by spines, stiff bristles, or hooks : this is the 

 case in Gad-flies, Crane-flies, and some others. 

 The bodies of the larva?, in some orders of insects^ 

 have inferiorly, and towards the head, six feet, each 

 formed of three small joints ; the last of which is 

 scaly, and terminates in a hook : this is usual in the 

 larva? of Beetles and Dragon-flies. The larva? of 

 Butterflies and Moths, besides six scaly articulated 

 feet, have a variable number of other false feet, 

 which are not jointed, but terminate in hooks, dis- 

 posed in circles and semicircles. These hooks, 

 which are attached to the skin by a kind of retractile 

 tubercles, serve as cramps to assist their motion on 

 other bodies. The larva? of those insects that un- 

 dergo only a semi-metamorphosis, as the Crickets, 

 Cock-roaches, and others of the order Hemiptera, 

 and the larva? of the insects that have no trans- 

 formation, as in the Aptera (the Flea excepted), 

 differ in no respect, as to their feet, from the per- 

 fect insects. — In this larva? state many insects re- 

 main for months, and others for a year, or some- 

 times even for two or three years ; increasing some- 

 what in size as they grow older, and occasionally 

 3 



