vi Proceedings of the South African PhUosoiihical Society. 



Among several kinds of white ants {Termitince) , the caste called 

 Soldiers produces a rattling sound. According to Haviland, one of 

 the species (Termes carhonarius) has reached the highest stage 

 of development in this direction, for the soldiers can hammer in 

 rhythmic unison. "■ At first a few begin irregularly, then they get 

 into time, and the others take it up. Every soldier in the exposed 

 portion of the nest, after the nest has been opened, stands up and 

 hammers with his head ; the blow is given thrice in very quick 

 succession, and then there is an interval of two seconds." 



This peculiarity cannot, however, be connected with sexual pur- 

 poses owing to the sex of the operators. 



Pkonation for defensive 2^ur2)oses. 



In addition to this love-chirping, my observations have led me 

 to the conclusion that the development of the music-producing 

 apparatus is not merely connected with wooing purposes, but is, 

 more particularly in many, if not in all the acridiiform Q^dipodi, a 

 means of defence by intimidation when threatened with capture. I 

 have already mentioned, when treating of colouration, that some of 

 the South African CEdipods of the genera Galoiotenus, Cosmorhysa, 

 Acrotylus, &c. (which harmonise so wonderfully with the soil on 

 which they squat), display in their short, very jerky flight the 

 brilliant colouring of their under wings, but what I have not yet told 

 you is, that at the same time they give out, while on the wing, a 

 very shrill, rattling noise, which, with perhaps the exception of the 

 ubiquitous ^dalus marmoratus and A. nigro-fasciatus, they seldom 

 make use of, at least in such a key, for courting purposes. 



It is also worthy of note that in the South African Lociistince, 

 Hetrodes and Eugaster, in which the stridulating organs are very 

 short, but similarly developed in both sexes, the highly resounding, 

 but always short, rasping noise produced is mostly heard when cap- 

 ture is threatening, or when the animal is alarmed. 



During a collecting trip to Namaqualand, I found that in the 

 neighbourhood of O'okiep any dwarfish bush left alive after a long 

 prolonged drought was tenanted by two species, Hetrodes pupa and 

 Eugaster vittatus, whose presence was revealed to me merely by the 

 piercing rasping noise not twice repeated, which the projection of 

 my shadow seldom failed to elicitate. 



In our Toad-Locusts {EremohiincE, PamphagiencB) a similar adap- 

 tation occurs, and in spite of some expressed erroneous deductions, 

 I can assert that very seldom, and then only at dusk, did the 

 examples of Methone Anderssoni, which I kept under observation, 



