Proceedings of the South African Philosoi^hiccd Society. v 



earned to the insect the Caffre name of *' Groounya." I have heard 

 it at Seymour, in the Cape Colony ; it is most impressive. 



Other Orders of Insects. — The Pneufiiorince, hov^^ever, are not the 

 only insects in which the abdomen has become hugely inflated for 

 sound-producing purpose, and among a quite different order, the 

 Cicadce, we have an analogous case in Tettigonia vespiformis. 



You have doubtless all heard in the Cape Peninsula the shrill 

 noise produced by the Oicadce, called here " Singeetjees." Bad as 

 it is, there is no comparison with what obtains on the West Coast of 

 Madagascar, where I was once compelled to abandon a Kabari held 

 with the natives owing to the piercing, deafening noise proceeding 

 from the adjoining tamarisk-trees, where a number of CicadcB were 

 holding their concert. 



In Cicadce the male only is musical, the female being voiceless. 

 This was known to remote antiquity, and poetic wags, at least one 

 of them, have made use of this tit-bit of natural history knowledge 

 for comparison, which, like most comparisons, is of course odious. 

 The sound-producing apparatus in the Cicadce is very different from 

 that of the other insects. The structure is partly thoracic and partly 

 abdominal, and the sound is produced by three ventral membranes, 

 one of which, the timbal, vibrates at the same time as the others, 

 the whole body acting as a resounding board in order to possibly 

 modify or increase the sound. This sound, however, in the case of 

 our two common species here, seems to be always pitched in the 

 same key. Another species, Tympany stria trichiosoma, Walk., not 

 uncommon round Cape Town, is almost mute on trees, but punctuates 

 the curve of its flight by a short, click-like note. 



In the Lepidopteea the males of some species also produce a 

 clicking noise when on the wing. 



Stridulating or noise -producing organs are probably more common 

 in CoLEOPTEEA and other orders of insects than it is supposed. Bedel 

 has found one on the legs of a Carahid also represented in South 

 Africa. But some insects produce sound without special noise- 

 producing organs. 



The death-w^atch, Anohium striatum, which has found a home here, 

 produces its well-known ticking noise by striking its head against 

 the wood ; this is connected with sexual purposes. 



With sexual purposes must also be connected the singular habit 

 of the male of the numerous species of the Tenebrionid genus 

 Psammodes, of striking the ground with the abdomen, and producing 

 thus at dusk, or at night, a very audible noise which has earned to 

 it the local name of " Tock Tockie," one of the rarely appropriate 

 vernacular names applied at this end of the- African Continent. 



