94 A. M. Mayer—Researches in Acoustics. 
receptors of aerial vibrations, as I will soon show by conclusive 
experiments. Neither can I agree with him in supposing that 
the antenne are only tactile organs, for very often their position 
and limited motion would exclude them from this function ;* 
and, moreover, it has never been proved that the antennz, which 
differ so much in their forms in different insects, are always tactile 
organs. ‘They may be used as such in some insects; in others, 
they may be organs of audition; while in other insects they may, 
as Newport and Goureau surmise, have both functions ; for, even 
granting that Miiller’slaw of the specific energy of the senses ex- 
tends to the insects, yet the anatomy of their nervous system is not 
sufficiently known to prevent the supposition that there may be 
two distinct sets of nerve fibers in the antennz or in connection 
known that when one of them vibrates, the other will be set into 
vibration by the impacts sent to it through the intervening air. 
Thus, if the fibrille on the antennz of an insect should be 
tuned to the different notes of the sound emitted by the same 
insect, then when these sounds fell upon the antennal fibrils, 
the latter would enter into vibration with those notes of the 
sound to which they were severally tuned ; and so it is evident 
- that not only could a properly constructed antenna serve as @ 
receptor of sound, but it would also have a function not possi- 
ble in a membrane ; that is, it would have the power of analyz- 
ing a composite sound by the co-vibration of its various fibrille 
to the elementary tones of the soun 
The fact that the existence of such an antenna is not only 
supposable but even highly probable, taken in connection with 
an observation I have often made in looking over entomological 
collections; viz: that fibrille on the antenne of noct 
insects are highly developed, while on the antenne of diurnal 
insects they are either entirely absent or reduced to mere rudi- 
‘mentary filaments, caused me to entertain the hope that I should 
