EXTERNAL ANATOMY OF INSECTS. 425 
* enter more into detail in another place. Their motion 
seems restrained, at least in some, to two directions, to- 
wards and from the mouth. They were called palpi, or 
feelers, because the insect has been supposed to use 
them in exploring substances. There seem to be no 
organs in the vertebrate animals directly analogous to 
the palpi of insects and Crustacea, unless, perhaps, the 
cirri that emerge from the lips of some fishes, as the 
cod, red mullet, &c. which Linné defines as used in ex- 
ploring (pretentantes). Whether the vibrisse, miscalled 
smellers, of some quadrupeds and birds have any refer- 
ence to them, I will not venture to affirm; but the feline 
tribe evidently use their bristles as explorers, and they 
are planted chiefly in the vicinity of the mouth. 
Having made these general remarks, | shall now con- 
fine myself to the labial palpi. I call them ladzal palpi, 
because that term is in general use, and because in many 
cases they really do emerge from what I consider as the 
labium, as in most of the chafers ; but they might with 
equal propriety be denominated /zngual palpi, since they 
sometimes appear to emerge from the fongue, as in the 
stag-beetle (Lucanus Cervus). In some instances, as in 
the Predaceous beetles, they seem to be common to both 
labium and tongue, being attached at their base on the 
upper side to the former, and on the under side to the 
latter. As to their stuation: they emerge from the base 
of the /abzum in the locusts (Locusta)? ; from its middle 
in Hister maximus’; from its summit in Amblyterus ¢ ; 
and from its lateral margin in Dynastes, &c. They con- 
sist of from one to four joints; which, I believe, they 
a Pratt VI. Fie. 6. b!'. ” Hor, Entomolog. i. t. 1. f. 1, g. 
© Thid.t. ii f. 18. g. 
