iv Proceedings of the South African Philosophical Society. 



always, or nearly always, greatly developed, for most, if not all the 

 AcridiincB are, or were once upon a time, saltatorial insects, play the 

 chief role here, and the rasping, rattle-like noise is produced by 

 the friction of the inner face of the femur against the outer face of 

 the upper wing, or against the asperities of the abdomen when the 

 wings are absent. 



The auditory organs are in the shape of a tympanic cavity closed 

 by a membrane, and situate near, over, or alongside the articulation 

 of the said hind thigh. These ears exist in both sexes. 



I do not know of any more pleasant, lazy occupation than to 

 watch in a piece of stubble some (Ediponince doing their courting. 

 If you have once been told of it, you cannot fail afterwards to notice 

 that a male which has already loudly proclaimed to the world that 

 he intends to win a mate, does occasionally move his thighs in 

 precisely the same manner as when producing sound ; yet no sound 

 is audible to us ; the female likewise will agitate her femora 

 rhythmically, but no sound is audible to us. Does it, however, 

 follow that the sound is not audible to them? The resounding 

 board is too close to the instrument for them not to perceive the 

 sound, of which they are the best judges. I have often witnessed 

 a mating so suddenly accomplished as to imply, seemingly, a com- 

 plete or partial understanding, between the two parties — an under- 

 standing possibly communicated in a subdued tone. 



In addition to these striking examples of sound-producing 

 CEdipods, we have in South Africa, and restricted so far to South 

 Africa, the most aberrant type of a musical grasshopper yet 

 discovered. This ^is the " Blaso2)," ten species of which are now 

 known to me. 



In some of these extraordinary insects {Pncicviorinm), four species 

 have most conspicuous silver-white patches. In one of them, 

 Cystoccelia scutellaris, the female is resplendent with longitudinal 

 silvery bands edged with pink or magenta, and is one of the very 

 rare cases in insect life where the female is more gorgeously 

 coloured than the male, the latter having only a few, and smaller 

 patches on the thorax and upper wings. The female is only partly 

 apterous, and cannot fly, but the male is fully winged. The femora 

 in both sexes, instead of being large and broad, are slender, but the 

 abdomen has acquired in the male the form of a huge transparent 

 vesicle the better to act as a sounding board. On the side of the 

 second basal abdominal segment there is a short sub-arcuate series 

 of triangular serrate teeth against which is rubbed a short but 

 elongated serrulate file situated in the inner part of the thigh. The 

 noise, produced at night, is short, but deep and loud, and it has 



