358 



SEXUAL SELECTION. 



Part II. 



in the male the whole body has been converted into a 

 musical instrument, being distended with air, like a 

 great pellucid bladder, so as to increase the resonance. 

 Mr. Trimen informs me that at the Cape of Good Hope 

 these insects make a wonderful noise during the night 



Fig. 14. Pneumora (from specimens in the British Museum). Upper figure, male ; 



lower figure, female. 



There is one exception to the rule that the females 

 in these three Families are destitute of an efficient 

 musical apparatus ; for both sexes of Ephippiger (Lo- 

 custidae) are said 40 to be thus provided. This case may 



40 Westwood, ibid. vol. i. p. 453. 



