CONSCIOUS PROTECTIVE RESEMBLANCE. 549 
tinuous ear-piercing scream of a number of the large Pweilopsaltria 
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. Perey Rendall 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). 
1t 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 xsthetic 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. 
