308 MOtlONS OlP INSECTS. 



that have more than six feet move in this way — which 

 is not improbable — from the difficulty of attending at 

 the same time to the movements of so many members, 

 is not easily ascertained. 



The dog-tick {Ixodes JRicinus, F.), if when young 

 and active it moves in the same way that it does when 

 swoln to an enormous size with blood, seems to afford 

 an exception to the mode of walking just described. It 

 first uses, says Ray, its two anterior legs as antennae 

 to feel out its way, and then fixing them, brings the 

 next pair beyond them, which bein^- also fixed, it takes 

 a secoud step with the anterior, and so drags its bloated 

 carcase along ^. — Redi observes, that wlien scorpions 

 walk they use those remarkable comb-like processes at 

 the base of their posterior legs to assist them in their 

 motions, extending them and setting them out from 

 the body, as if they were wings : and his observation is 

 confirmed by Amoreux, who calls them ventral swim- 

 mers**. — I have often noticed a millepede (Juhts ter- 

 restris, L.), frequently found under the bark of trees, 

 and where there is not a free circulation of air, the 

 motions of which are worthy of attention. Observed at 

 a little distance, it seems to glide over the surface, like 

 a serpent, without legs ; but a nearer inspection shows 

 how its movement is accomplished. Alternate portions 

 of its numerous legs are extended beyond the line of 

 the body, so as to form an obtuse angle with it, while 

 those in the intervals preserve a vertical direction. So 

 that, as long as it keeps moving, little bunches of the 

 legs are alternately in and out from one end to the 

 other of its long body ; and an amusing sight it is to 

 • Hist. Ins. 10. " Redi Opiisc. i. 80. Amofeux, 44— 



