236 ZOOLOGY. 
had an experience of the same kind. A cocoon which hung in 
her store produced a female moth, and within the next two days 
her store was visited by half a dozen of the male insects. Can 
‘any one tell me what fine sense this may be which guides this - 
insect so far, and into such strange places in search of his waiting 
mate?—F. E. L. Brat, Fitchburg, Mass., July 7, 1873. 
[We print the above as fair examples of “assembling” among — 
moths. Nearly every entomologist has had similar experiences. 
It is a common occurrence. We are disposed to think that the 
male is guided by the sense of smell, as the antennz of the silk- 
moths probably possess this as well as the sense of hearing— — 
ITORS. | a 
ORGANS OF Hearing 1N Insects.—At, the last meeting of the 
National Academy of Sciences, Professor A. M. Mayer exhibited 
experimental confirmation of the theorem of Fourier as applied by. 
him in his propositions relating to the nature of a simple sound, 
and to the analysis by the ear of a cornposite sound into its ele- 
mentary pendulum-vibrations ; and to show experiments elucidating 
the hypothesis of audition of Helmholtz. Placing a male mosquito 
under the microscope, and sounding various notes of tuning-forks 
in the range of a sound given by the female mosquito, the various — 
fibres of the antennz of the male mosquito, vibrated sympathet- i 
ically to these sounds. The longest fibres vibrated sympathetically 
to the grave notes, and the short fibres vibrated sympathetically to 
the higher notes. The fact that the nocturnal insects have highy 
organized antennze, while the diurnal ones have not; and also the 
fact that the anatomy of these parts of insects shows à highly ah 
veloped nervous organization, lead to the highly probable inference 
that Prof. Mayer has here given facts which form the first sure base 
of reasoning in reference to the nature of thé auditory apparatus © 
insects. oo 
These experiments were also extended in a direction whieh 
added new facts to the physiology of the senses. If a sonor n 
impulse strike a fibre so that the direction of the impulse is mt 
direction of the fibre, then the fibre remains stationary. But 
the direction of the sound is at right angles to the fibre, the SP 
. Vibrates with its maximum intensity. Thus, when a sound 5e 
the fibrils of an insect, those on one antenna are vibrated ‘ 
powerfully than the fibrils on the other, and the insect nasii 
