350 TROPICAL NATURE 



flies, so that it is really a living trap, and forms its own 

 bait! 1 



All who have observed animals, and especially insects, in 

 their native haunts and attitudes, can understand how it is 

 that an insect which in a cabinet looks exceedingly con- 

 spicuous, may yet when alive, in its peculiar attitude of 

 repose and with its habitual surroundings, be perfectly well 

 concealed. We can hardly ever tell by the mere inspection 

 of an animal whether its colours are protective or not. No 

 one would imagine the exquisitely beautiful caterpillar of the 

 emperor-moth, which is green with pink star-like spots, to be 

 protectively coloured ; yet, when feeding on the heather, it 

 so harmonises with the foliage and flowers as to be almost 

 invisible. Every day fresh cases of protective colouring are 

 being discovered, even in our own country; and it is becoming 

 more and more evident that the need of protection has played 

 a very important part in determining the actual coloration 

 of animals. 



Warning Colours 



The second class the warning colours are exceedingly 

 interesting, because the object and effect of these is, not to 

 conceal the object, but to make it conspicuous. To these 

 creatures it is useful to be seen and recognised ; the reason 

 being that they have a means of defence which, if known, 

 will prevent their enemies from attacking them, though it is 

 generally not sufficient to save their lives if they are actually 

 attacked. The best examples of these specially protected 

 creatures consist of two extensive families of butterflies, the 

 Danaidse and Acrseidse, comprising many hundreds of species 

 inhabiting the tropics of all parts of the world. These 

 insects are generally large, are all conspicuously and often 

 most gorgeously coloured, presenting almost every conceivable 

 tint and pattern ; they all fly slowly, and they never attempt 

 to conceal themselves ; yet no bird, spider, lizard, or monkey 

 (all of which eat other butterflies) ever devours them. The 

 reason simply is that they are not fit to eat, their juices 

 having a powerful odour and taste that is absolutely dis- 

 gusting to all these animals. Now we see the reason of their 



1 These cases form a distinct sub-group of "alluring coloration." See 

 Dancinism, p. 210. 



