52 The Colours of Animals 



of the ocean, adapted to the colour of the sand. So, also, 

 are those sylvan birds, which quit the dense umbrage of 

 healthy growing trees, to seek their food and expose them- 

 selves on bare trunks and leafless decaying branches, of the 

 hue of their particular haunts. " So exquisitely are they 

 fitted for their office," says Mr. Mudie *, " that the several 

 woodpeckers vary in tint with the general colours of the trees 

 which they select. If it is an alternation of green moss, 

 yellow lichen, and ruby tinted cups, with here and there a 

 spot of black, then the green woodpecker comes in charge ; 

 but if it is the black and white lichens of the alpine forest or 

 the harsh-juiced tree, then we may look for the spotted races 

 upon the bark." The wryneck is the colour of the lichened 

 branch ; and the night swaliow and the owls resemble their 

 peculiar places of concealment. So, also, the gayer colours of 

 nocturnal moths are always on the hinder wingsf, and the 

 anterior, which, when they rest, conceal these, are adapted to 

 the hues of the various places where by day they are found : 

 even the bright upper wings of the tiger moths (A'rctia Cajtf, 

 and A. villica) are with difficulty recognised upon a lichened 

 bank or paling.J It is curious, indeed, the resemblance which 

 subsists between the colours of nocturnal birds and night 

 Lepidoptera; the buff tip moth (Pygae v ra bucephala) thus 

 reminds us of the barn owl (Strix vulgaris); and the goat 

 moth (Cossus Ligniperda), and a host of others, are similar in 

 their tints to most of the &trigidae : in both cases they are 

 doubtless intended for the same purpose, that of concealment. 

 It would indeed be easy to extend this list of examples con- 

 siderably further; but I shall only now mention the common 

 hare, which, when in form, would hardly ever be seen were it 

 not for its brilliant eye ; if its eye were closed, which it pro- 

 bably was before its quick sense of hearing had warned it of 

 our approach, it would almost always, perhaps, wholly escape 

 our observation. This ever continued watchfulness must 

 have given rise to the supposition, that the hare always sleeps 

 with its eyes open. 



Seeing, therefore, so many most striking adaptations of colour 

 to haunt, in cases where the concealment thus afforded can 

 be the only purpose, I think it is not too much to infer, that 

 the changes of colour in many arctic animals were intended 



* See Mudie's Feathered Tribes of the British Istands, i. 190. 



f Among day-flying Lepidoptera, the more gaudy colours are usually on 

 the fore wings. 



% Animals of bright and gaudy colours are generally very retiring in 

 their habits : even the common robin mostly turns away his breast as you 

 approach. 



