SENSES. OF INSECTS. 243 
structure than others—a circumstance which is often cha- 
racteristic of the made insect*: but if we examine such 
antenne, we shall find that their most sensztzve parts can- 
not come in contact with the earth or other bodies for 
exploring their way; but having thus a greater surface 
exposed to the action of the atmosphere, they have more 
points to receive vibrations, or any pulses or other no- 
tices communicated to it. It is thus, probably, that in 
their flights, when they approach within a certain di- 
stance, they discover the station of the other sex. Even 
the plumose antennz of male gnats may in some re- 
spects thus be acted upon. In the Lamellicorn beetles, 
the knob of these organs in both sexes consists of lamine, 
the external ones on their outside, of a corneous sub- 
stance; while their internal surface, and the inner laminz 
—which are included between them, as an oyster between 
the valves of its shell—are covered with nervous pa- 
pilla. If you examine the proceedings of one of these 
little animals, you will find before it moves from a state 
of repose that its antennee emerge, and the laminze di- 
verge from each other; but that it does not apply them 
to surfaces to explore its way, but merely keeps them 
open to receive notices from the atmosphere. Even szm- 
ple antennze are often employed in this way, as well as 
for touch. I once noticed a species of Phryganea L., 
(one of those with these organs very long,)that was perch- 
ed upon a blade of grass; its antennze vibrated, and it 
_ kept moving them from side to side in the air, as if thus 
by aéroscepsy it was inquiring what was passing around 
it. Dr. Wollaston has an observation bearing so pre- 
* Vor. IIL. p. 320—. 
ee 
