4 
INTRODUCTION. 
single filaments, sometimes furnished with bristles or 
hairs, which give them a comb-like or feather-like 
appearance ; now they are thickened at the bottom, 
now at the top ; now the last joints are formed of 
broad laminae or plates; they are usually attached to 
the front of the head between the eyes. It is not 
definitely known what is the use of the antennae, beyond 
the fact that they are organs of touch, but as such 
only play a subordinate part. It has been supposed by 
some that they are organs of hearing. From the 
researches of M. Lespds, Erichson, and Dr. J. B. Hicks,, 
it would appear that the antennae of insects are organs 
of hearing ; it is said “ they consist of a cell, sac, or 
cavity filled with fluid, closed in from the air by a. 
membrane analogous to that which closes the foramen 
ovale in the higher animals ; that this membrane is for 
the most part thin and delicate, but often projects 
above the surface, in either a hemispherical, conical, or 
canoe-shaped, or even hair-like form, or variously 
marked; that the antennal nerve gives off branches 
which come in contact with the inner wall of the sacs.’ * 
On the other hand it is asserted that the antenna) are 
partly organs of smell; on this point Mr. Lowne says, 
“ I believe myself that this is the organ of smell, 
although I by no means consider the antenna) of all 
insects are necessarily olfactory organs. I think in 
many instances they are merely feelers. Perhaps the 
beautiful feather-like antenna) of male moths are sexual 
ornaments, although they may have special olfactory 
organs connected with them; and possibly the laminated 
* Trans. Lin. Soc. Vol. xxr*, pt. 4. 
