808 MOTIONS OF INSECTS. 
time’; but this is contrary to fact, and indeed would 
make their ordinary motions, instead of walking and 
running, a kind of canter and gallop. Whether those 
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 (Irodes Ricinus, 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 ex- 
ception to the mode of walking just described. It first 
uses, says Ray, its two anterior legs as antennz to feel 
out its way, and then fixing them, brings the next pair 
beyond them, which being also fixed, it takes a second 
step with the anterior, and so drags its bloated carcase 
along’. Redi observes, that when scorpions walk they 
use those remarkable comb-like processes at the base of 
their posterior legs to assist them in their motions, ex- 
tending them and setting them out from the body, as if 
they were wings: and his observation is confirmed by 
Amoreux, who calls them ventral swimmers*. I have 
often noticed a millepede (Julus terrestris, 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 accom- 
plished. Alternate portions of its numerous legs are ex- 
tended beyond the line of the body, so as to form an ob- 
tuse angle with it, while those in the intervals preserve 
? ili, 284. b Hist. Ins. 10. © Redi Opusc. i. 80. Amoreux, 44— 
