84 ANIMAL COLOEATION. 



colours " has been placed in the central hall of the Natural 

 History Museum at South Kensington. 



Mr. Wallace includes all these instances under the heading 

 of " General Protective Eesemblance," to distinguish them 

 from other instances, to be treated of immediatelj', in which 

 the animal shows a special resemblance to some particular 

 object, such as a leaf or twig. 



Perhaps the " ajatumn tints," so remarkably shown in 

 certain moths which emerge from the chrysalis during the 

 latter months of the year, are to be referred to the same 

 category. Several species of British moths belonging to the 

 genus Xanthia have the upper wings of a yellowish brown 

 colour, like dead leaves, often mottled with darker colours in 

 a way highly suggestive of more thoroughly decayed portions 

 of the leaf ; and these moths are found in the perfect state in 

 the autumn months. 



The white colour of many Arctic animals has been treated 

 of in Chap. II., as they come into the class of colours which 

 change in correspondence with changes in the environment. 



The dusky colours of nocturnal animals — ^particularly of lepi- 

 doptera and birds — have been used as an instance of a similar 

 compliance with environmental conditions ; dusky colours and 

 darkness seem to suit. It is true that there are no brilliantly 

 coloured nocturnal birds ; but there are brightly coloured 

 nocturnal moths. Any lepidopterist who has " sugared " in 

 the New Forest knows the brilliancy of the tints exhibited by 

 the Crimson Underwing, the broad-bordered Yellow Under- 

 wing, and the more delicate but equally beautiful and con- 

 spicuous colours which adorn the upper wings of the " Peach 

 Blossom " and " Merveil du Jour." One would, in fact, expect 

 that brilliant coloration would be the rule rather than the 

 exception among nocturnal insects, for, however bright and 



