326 MOTIONS OF INSECTS. 



longs a . All these insects have the terminal sucker 

 between the claws, three foot-cushions on the first 

 joint of the tarsus, and one on the second b ; and the 

 same conformation also distinguishes the feet of Trux- 

 alis c . In the specie's of Acrydium, F. (Tetrix, Latr.), 

 the foot-cushions, I believe for in the dead insect they 

 are the reverse of conspicuous are arranged nearly as 

 in the two preceding genera, but these insects are with- 

 out the claw-sucker. And lastly, Gryllus has neither 

 suckers nor cushions. From this statement it seems to 

 follow since Blatta, Phasma, and Mantis, that do not 

 leap, are provided with cushions ; and Gryllus> a heavy 

 tribe of insects that does, are without them that their 

 object cannot be exclusively to break the fall of the 

 insects that have them. And for the same reason we may 

 conclude, that they must have some further use than 

 augmenting their elasticity when they jump. When we 

 consider that the Blattce many of which have no suckers, 

 or very small ones are climbing insects (I have seen 

 B. Germanica run up and down the walls of an apart- 

 ment with great agility), and that the long and gigantic 

 apterous spectres, &c. (Phasma) require considerable 

 means to enable them to climb the trees in which they 

 feed, and to maintain their station upon them, we may 

 conclude that these cushions, by acting in some degree 

 as suckers, may promote these ends. 



Amongst the homopterous Hemiptera, Chermes and 

 many of the Cercopidce* are furnished with the claw- 

 suckers ; but the noisy Cicada, as well as the heteropte- 



a See Zoolog. Jour, for 1825. No. iv. 431. 

 h Philos. Trans. 1816. t. xxi./. 1-9. 



c The orthography of this name is TroxaUis, from the Greek 

 c, Gryllus. d De Geer, iii. 132. 173. 



