SENSES OF INSECTS. 257 
are better calculated to assist an insect in threading the 
dark and tortuous labyrinths through which it has often 
to grope its way, and where antennas cannot be employed. 
I have noticed that Hydrophili — in which genus the 
palpi are longer than the antennae — when they swim, 
have their antennae folded ; while the former are stretch- 
ed out in front, as exploring before them. As these 
are attached to the under-jaws and under-lip, we may 
suppose they are particularly useful to insects in taking 
their food; and upon this occasion I have often observed 
that they are remarkably active. I have seen Byturus 
tcnnentosus, a beetle which feeds upon pollen, employ 
them in opening anthers ; and the maxillary pair appear 
to me to assist the maxillae in holding the food, while 
the mandibles are at work upon it. 
The arms or fore-legs of some insects are also organs 
of active touch, being used, as we have seen, for cleaning 
the head, digging, repairing their dwellings, and the 
like a . By the Ephe?nerce y which have very short an- 
tennae, the fore-legs, when they fly, are extended before 
the head, parallel with each other and quite united — pro- 
bably to assist in cutting the air. The Trichoptera use 
their antennae for the same purpose. 
Another sense of which the organ seems uncertain is 
that of smelling, and various and conflicting opinions 
have been circulated concerning it. Christian thought 
that insects smell distant objects with their antenna, and 
near ones with their palpi b . Comparetti has a most sin- 
a Vol. II. p. 361—. III. p. 544—. " Lehmann De Sens, 
Extern. §c. De OlfactU. 
VOL. IV. S 
