CxXv 
T need not dwell on these memoirs, nor on the numerous entomo- 
logical contributions which have appeared in the ‘ Zoologist,’ the 
‘Entomologist, the ‘Entomologist’s Monthly Magazine, or Mr: 
Stainton’s ‘ Annual, because they are in the hands of all our 
members. 
The ‘ Journal of the Linnean Society’ also contains entomological 
memoirs by Messrs. Pascoe (2), Butler, M‘Lachlan (2), Spruce, and 
Bates. 
The ‘Zeitschrift fiir Wissenshaftliche Zoologie’ has been particularly 
rich this year in entomological communications. 
Dr. H. Landois has published in it a very interesting memoir* on the 
sounds produced by insects. He commences with a short historical 
sketch of the subject, referring especially to the observations of 
Aristotle, “ the greatest of naturalists ;’ he might almost have said “ the 
greatest of men.” He then describes successively the mechanism by 
means of which sound is produced among the Orthoptera, Coleoptera, 
Diptera, Homoptera, Lepidoptera, Hymenoptera and Neuroptera. 
The number of insects which emit audible sounds is very large, 
and there can be no doubt that many more produce tones which, 
though inaudible to us, are perceptible to one another. This is 
shown by the fact that many species which are apparently silent 
possess arrangements evidently intended for the production of sound. 
The familiar sounds of the Orthoptera have no claim to be regarded 
as a voice, but are produced by rubbing one part of the body against 
another. A few, but very few, of the Lepidoptera emit sounds, which 
are made by rubbing the palpi against the trunk, and cease if the 
palpi are removed. 
Among the Coleoptera also sounds are generally produced by 
friction, and the wings often produce a humming noise during flight. 
In the genus Melolontha there is a second source of sound, which 
may almost be called a voice. In the large trachea, immediately 
behind each spiracle, is a chitinous process or tongue, which is thrown 
into vibration by the air during respiration, and thus produces a 
humming noise. 
Similar structures occur in many Diptera, Hymenoptera, Neuroptera 
* Zeits. f. Wiss. Zool. Vol. xvii. Pt. 1. 
