SENSES OF INSECTS. 24-5 
were very merry, and continued singing all the day; but 
a rap at the door would stop them instantly. By prac- 
tice he learned to imitate their chirping : when he did 
this at the door, at first a few would answer him in a 
low note, and then the whole party would take up the 
tune and sing with all their might. He once shut up 
a male in his garden, and gave the female her liberty ; 
but as soon as she heard the male chirp, she flew to him 
immediately 2 . 
But although physiologists are for the most part agreed 
that insects have the ordinary five senses of vertebrate 
animals, yet a great variety of opinions has obtained as 
to their external organs ; so that it has been matter ot 
doubt, for instance, whether the antenna are for smell, 
touch, or hearing ; and the palpi for smell, taste, or 
touch. Nor has the question, as it appears to me, b±en 
satisfactorily decided : for though it is now the most 
general opinion that the primary use of antennas is to 
explore as factors, yet by the most strenuous advocates 
of this opinion they are owned not to be universally so 
employed; so that granting this to be one of their prin- 
cipal functions, yet it seems to follow that there may be 
another common to them all, which of course would be 
their primary function. We are warned, however, not 
to lay any stress upon the argument to be drawn from 
analogy ; and told that we might as well dispute about 
the identity of the nose of a man, the proboscis of the 
elephant, the horn of the rhinoceros, the crest of the 
cock, or the beak of the toucan b . But this is merely 
* Lehmann De Sens. Extern. Animal. E.vsang. 22 — . 
b Ibid. I)c Antenn. Insect, ii. 7». 
