ON THE FUNCTIONS OF THE ANTENNZ. 591 
and names of the first rank come before us in the investigation 
of the history of this controversy; no subject, perhaps, in 
zoology has been treated with greater acumen, and yet to-day 
(1883), in spite of the many essays of the last ten years, we are 
far from a final solution of the questions involved.’ 
Krapelin gives references to more than one hundred papers 
on the subject, ranging from 1730 to 1883. 
Lubbock [276], in 1888, said: ‘The evidence is, I think, 
conclusive that the antenne are olfactory as well as tactile 
organs, and I believe that they also serve as organs of 
hearing.’ 
Observations in Favour of an Auditory Function.—Kirby (‘ Intro- 
duction to Entomology’) observed movements of the antennz 
in a Moth and in a Weevil when he made a distinct sound in 
their vicinity, and other observers have asserted that the 
antennz are set into vibration by sounds. Mayer went a step 
further, experimenting with the feathered antenne of a male 
mosquito (Culex), he found that some of the hairs are thrown 
into vigorous vibration, when a note with 512 vibrations per 
second is sounded. Lubbock [276], who quotes the observa- 
tion, adds: ‘It is interesting to observe that the hum of the 
female Gnat corresponds nearly to this note, and would, conse- 
quently, set the hairs into vibration.’ To my ear, however, the 
note of the female Gnat is certainly not middle C, which has 
512 vibrations, but A, as is usually stated with 420 double 
vibrations. 
It may be remarked that the vibration of the sete in response 
to certain notes is a physical necessity, but it is not evidence 
that they are endowed with auditory sensibility ; neither is the 
voluntary movement of the antennz when an insect is excited 
by sound better evidence. A terrier will certainly sniff when 
he hears a rat, but this is not evidence that he hears with his 
nose; the dog is simply using his most acute sense to determine 
the cause of a sound. And so insects may use their antenne 
when excited by sounds, even if they do not hear with them. 
Lehmann [261] believed that insects hear with their antennz, 
and he found that those of a Cricket (Acheta domestica) vibrate 
39 
