278 
NOTES AND MEMORANDA. 
If a slightly fluid substance, which only dries slowly in the air, is 
coated over the wing-stump of an animal, operated upon in the 
manner just described, the preceding sound is sensibly deadened, 
without the stigmata being in any way modified, or the movement of 
the wings impeded. 
When the section includes the stump itself, the sound becomes 
sharper and weaker. It ceases as soon as a sensitive part is reached ; 
but, as may easily be made evident, it is only because the animal then 
ceases to execute movements which have become painful. 
To sum up, in the Hymenoptera and the Diptera the buzzing is 
due to two distinct causes ; the one being the vibrations of which the 
articulation of the wing is the seat, and which constitute the real 
buzzing ; the other, the friction of the wings against the air, an effect 
which more or less modifies the former. It w^ould not be impossible, 
after these data, to reproduce artificially the buzzing of these animals, 
and I have some hope of succeeding. 
Among the powerful-winged Lepidoptera, such as the Sphinxes, 
the soft and mellow humming which these animals make is only due 
to the rustling of the air by their wings. This sound, always grave, 
is the only one produced ; it is not accompanied by basilary beatings, 
owing to a special organization, and chiefly to the presence of scales. 
Among the Libellulm also, the base of whose wings is furnished 
with soft and fleshy parts, there does not exist any real buzzing, but a 
simple noise due to the rustling of the organs of flight.” * 
Although the following paragraph has now gone the round of 
the provincial (and some London) papers, having appeared in the 
‘ Times ’of 17th September, it will not be inappropriate to reprint it 
here in juxtaposition with the above note of M. Perez which appeared 
in the ‘ Comptes Eendus ’ of 2nd September : — 
“ The old naturalists thought generally that the buzzing of insects 
was produced by the vibrations of the wing, but they had scarcely 
attempted to analyze this phenomenon, and their opinion was abandoned 
when Eeaumur showed that when the wings are cut a blow-fly con- 
tinues to buzz. Other explanations of the phenomenon have been 
advanced by various naturalists, but none of them are satisfactory. 
M. Jousset de Bellesme has been making some investigations on the 
subject, and, after proving that previous theories are unsatisfactory, he 
describes the results of his own researches. To avoid confusion, it 
should be distinctly understood what is meant by buzzing. In the 
scientific acceptation it means to imitate the sound of the humble-bee, 
which is the type of buzzing insects. But the humble-bee gives out two 
very different sounds, which are an octave of each other — a grave sound 
when it flies and a sharp sound when it alights. We say, then, that 
buzzing is the faculty of insects to produced two sounds at an octave. 
This definition limits the phenomenon to the Hymenoptera and the 
Diptera. The Coleoptera often produce in flying a grave and dull sound, 
but they are pow^erless to emit the sharp sound, and consequently do 
not buzz. There are two or three ascertained facts which will serve 
as guides in the interpretation of the phenomenon. First, it is indis- 
* ‘ Comptes Eendus,’ vol. Ixxxvii. p. 378 . 
