PoTTEE. — On Netu Zealand Cicadas. 281 



significant fact, and, apart from all other considerations, lends 

 a distinct air of probability to the theories of those who believe 

 in the auscultatory powers of insects. It is contended by 

 some that the possession of a sound -producing apparatus 

 is no proof of the ability to hear. I maintain that it is 

 strong evidence in favour of that ability, and when such ap- 

 paratus is confined to one sex the hearing-powers in the 

 opposite sex become evident. When we come to examine 

 the male cicada and see Vv'hat a large part of it is occupied 

 by the sound -producing organs, such a highly -specialised 

 apparatus must be of importance in the welfare of the insect 

 in which ic occurs, and can only have been produced by some 

 very potent factor. Now, as these sounds are emitted only 

 by the male sex, my observations show me that the female 

 seeks the male instead of vice versa, which I think is strong 

 evidence that the female can hear, and is attracted by the 

 song of the male. My notes have been made on only two 

 species, which offer greater facilities for observation than the 

 others, and even in these it is very difficult to make accurate 

 observations, owing to the sluggishness of their movements, 

 the height at which they sit, and the fact that the male 

 and female are indistinguishable on the tree unless the male 

 happens to be singing, when the abdomen is slightly raised 

 and the wings held at a somewhat acute angle. 



I have watched solitary males when singing, and seen 

 another cicada advance from some other part of the tree with 

 a slow, somewhat jerky gait, stopping every now and then, 

 and passing and repassing the calling insect until it rests 

 alongside him. On netting such insects I have found them to 

 be females. I have noticed that when any females are near 

 a calling male the latter becomes very restless, walking back- 

 wards, forwards, and sideways, and giving a sharp flutter 

 with his wings as if to try and attract the attention of the 

 females. If the male utters his shrill cry for the purpose of 

 attracting the female, the explanation of the different calls of 

 the species at once can be seen, for if the female finds the 

 male by his call, and there are a number of different species 

 frequenting the same place, those males which acquire some 

 peculiarly distinctive sound would be likely to attract to them- 

 selves more females of their own kind, and thereby would 

 leave more progeny, than those males whose cry more closely 

 resembles that of another species, for these latter would be 

 apt to attract females of another species, with which they 

 could not interbreed ; and those females which are most apt 

 at distinguishing the notes of their own mates from those of 

 other species are more likely to pair and leave progeny. I 

 have several times imprisoned male cicadas in my breeding- 

 cage, which is 4ft. by 2ft., in twelve compartments of gauze 



