CHAP, ix RECOGNITION-MARKS 157 



Coloration for Concealment and for Visibility 



Colour and markings for concealment pervade all nature. 

 The hare on its form, the snipe in its covert, the vast 

 majority of birds while sitting on their nests, the sand- 

 coloured desert animals, and the prevalence of green colours 

 in the inhabitants of tropical forests, are a few of the best- 

 known examples. The uses of such colours in order to 

 protect the Herbivora from enemies, or to conceal those 

 which devour other animals from their prey, was at once 

 acknowledged, and it was seen how, with variability of colour 

 as a constant fact, survival of the fittest might soon bring 

 about the beautiful harmony of coloration we everywhere 

 find to prevail. But it was also undeniable that there were 

 almost equal numbers of animals of all classes and sizes, in 

 which colours and markings occurred which could not by 

 any possibility be interpreted as protective, because they 

 seemed to render the creature glaringly conspicuous. Some 

 of these, which were most prevalent among insects, were soon 

 explained as " warning colours," because they were exhibited 

 by species which were either so nauseous as to be inedible 

 by most insect-eaters ; or were armed with stings which 

 might cause great pain or even loss of life to an enemy 

 which attacked them. When it was found that many other 

 groups of insects which did not possess these protective 

 qualities, yet acquired the same colours and often the same 

 form ; and when my fellow - traveller on the Amazon, 

 H. W. Bates, showed how this peculiar kind of " mimicry " 

 was beautifully explained on the Darwinian hypothesis, not 

 only was the theory itself greatly strengthened, but a whole 

 host of curious and beautiful colour-phenomena in nature, 

 hitherto unnoticed, were seen to come under some form of 

 the same general principle. As one rather extreme example 

 of mimicry I give the figures of a black wasp with white- 

 banded wings, which is closely imitated by a heteromerous 

 beetle. These I captured myself in the forests of Borneo, 

 flying together near the ground. They are of nearly the 

 same size. The wing -coverts (elytra) of the beetle are 

 reduced to pointed scales, allowing the true wings to be 

 always extended. This is most unusual in beetles, as is the 



