SENSES OF INSECTS. 255 
posed to admit that the primary and most universal 
function of the antennas is to be the organs of a sense, if 
not the same, at least analogous to hearing, and answer- 
ing the same end; something perhaps between it and 
touch. In some, however, as has been found in the 
Crustacea, an organ of hearing, in the ordinary sense, 
may exist at the base of the antennae, which may act the 
part in some measure of the external ear, and collect 
and transmit the sound to such organ*. 
That numerous antennae, as a secondary function, ex- 
plore by touch, is admitted on all hands, and therefore I 
need not enlarge further upon this point ; but shall pro- 
ceed to inquire whether insects do not possess some 
other peculiar organs that are particularly appropriated 
to this sense. First, however, I must make some gene- 
ral observations upon it. Of all our senses, touch is the 
only one that is not confined to particular organs, but 
dispersed over the whole body : insects, however, from 
the indurated crust with which they are often covered, 
feel sensibly, it is probable, only in those parts where 
the nerves are exposed, by being covered with a thinner 
epidermis, to external action. Not that they cannot feel 
at all in their covered parts ; for as we feel sufficiently for 
walking, though our feet are covered by the thick sole 
a Marcel de Serres thinks he has discovered an organ of hearing 
in most insects, but he does not state its situation. Mem. du Mus. 
1819. 99. Treviranus, with regard to the Blattina, suspects it to be 
situated between the eye and the base of the antennae, perhaps al- 
luding to the spot noticed above. (Vol. III. p. 505.) Cams, who 
mentions the above, says, " Is it not reasonable to ask if the sense 
of hearing may not reside in the membrane which connects the an- 
tenna; with the head ?" Introd, to Comp. Anal. i. 80—. 
