CONSCIOUS PROTECTIVE RESEMBLANCE. 549 



tinuous ear-piercing scream of a number of the large Pcecilopsaltria 

 horizontalis, Karsch, which seems to make the whole air pulsate, with- 

 out betraying the exact locality of a single individual. Although in 

 many cases I have actually tracked down individuals by their cry, in 

 order to learn the calls of the different species, yet such a method is 

 far too laborious for ordinary collecting purposes. So experienced a 

 collector as Dr. Percy Kendall says : " In the Transvaal I have also 

 taken them at rest on tree-trunks, but I do not think they were taken 

 in consequence of their song having thus localized them. At Zomba 

 I caught a large species by actually localizing its noise, but that was 

 the only instance of the kind that I remember " (' Zoologist,' 1897, 

 p. 520). 



It must not be supposed that I do not recognize that the Cicada's 

 cry must, under certain circumstances, be dangerous for individuals 

 as, indeed, are many other secondary sexual characters ; but Mr. Distant 

 appears to have overestimated the danger, and the contention that this 

 noise invalidates their admirably protective colouration appears to be 

 an inverted way of looking at the question. It is more reasonable to 

 suppose that the protective resemblance of these insects is so effica- 

 cious, that they have been able to develop these extraordinary cries 

 through the process of sexual selection (or perhaps even natural 

 selection, supposing aesthetic appreciation on the part of the female be 

 denied), without unduly endangering the safety of the species. On this 

 view, the Cicada's song, far from proving that the insect's colouring is 

 inefficient for protective purposes, would stand as a testimony of its 

 very high efficacy. In fact, I venture to think that, in the vast majority 

 of cases in which animals produce conspicuously loud sounds, they will 

 be found to possess either highly protective colouration or habits, or else 

 distasteful or other qualities which render concealment unnecessary. 



In conclusion, I can only hope that sufficient has been said to show 

 that there are good grounds for opposing the suggestion that active 

 mimicry is of any general occurrence in the animal kingdom ; and, 

 further, that the attempt to minimise certain phenomena of ordinary 

 protective resemblance, in order to bring them within the scope of that 

 principle, is not justifiable upon the evidence adduced. The subject, 

 however, is such a wide one, that it is impossible to deal adequately 

 with all its aspects within the limits of a paper such as this. 



