NATURAL INCREASE. 
^57 
each other), the note is sometimes emitted ; while if 
dubiously received, or threatened with encasement, 
when introduced to a colony as an alien, her 
peculiar, plaintive call is almost certain to be heard. 
From previous explanations of the causes of buzzing 
and humming, we must, I think, dismiss the idea 
of either spiracles or breathing-tubes having anything 
to do with this singular phenomenon ; while the 
mouth, being merely an opening leading to the 
stomach, is necessarily incapable of any form of 
utterance. It is certain, also, that the wings are not 
concerned in its production, since queens clipped so 
vigorously that not a vestige of wing remains can 
be as noisy as others. Many insects, and some 
spiders and Crustacea, are favoured with natural 
musical instruments, formed of hard, wrinkled sur- 
faces, denominated “ stridulating organs,’’ which, by 
certain and varied movements of the bodies of the 
possessors, evoke grating, creaking notes. I re- 
member Professor Stewart showing, about a year 
since, at the Linnaean Society, the stridulating organ 
of the spiny lobster {Pah'nurus). The file-like bow 
was exhibited under the microscope ; and a male 
carapace, kept soft by glycerine, produced, when 
rubbed, the peculiar screeching rasp — something 
between the torture of the saw-sharpener and the 
quack of a duck — which is apparently so touchingly 
beautiful to the female Palinurus. To take only one 
other example : in the small, yellow, meadow ant* 
[Lasius flaviis) the third abdominal segment is 
* Sir J. Lubbock’s “Ants, Wasps, and Bees,” page 230. 
