126 
The Namralist in La Plata, 
spiders, wasps, and other dangerous kinds, that 
it is manifestly a warning colour,” the most 
universal and best^ known in nature ; and the 
grasshopper, I believe, furthermore mimics the 
fearless demeanour of the protected or venomous 
species, which birds and other insect-eaters know 
and respect. It might be supposed that the young 
Zoniopoda is itself unpalatable ; but this is scarcely 
probable, for when the deceptive black mask is 
once dropped, the excessive shyness, love of con- 
cealment, and protective colouring of the insect 
show that it is much sought after by birds. 
While setting this down as an undoubted case of 
mimicry,” although it differs in some respects 
from all other cases I have seen reported, I cannot 
help remarking that this most useful word appears 
to be in some danger of losing the meaning origi- 
nally attached to it in zoology. There are now 
very few cases of an accidental resemblance found 
between two species in nature which are not set 
down by someone to mimicry,” some in which 
even the wildest imagination might well fail to see 
any possible benefit to the supposed mimic. In 
cases where the outward resemblance of some 
feeble animal to a widely different and well-pro- 
tected species, or to some object like a leaf or 
stick, and where such resemblance is manifestly 
advantageous and has reacted on and modified the 
life habits, it is conceivable that slight spontaneous 
variations in the structure and colouring of the 
unprotected species have been taken advantage of 
by the principle of natural selection, and a case of 
‘^mimicry” set up, to become more and more 
