WARNING COLOURS 183 



eating animals are purely relative, and are manifested 

 to a marked extent when they are offered a variety 

 of insects, and when obviously nauseous species are 

 excluded from the list. 



Butterflies and moths are freely eaten by lizards, 

 but they are not enjoyed like houseflies or many cater- 

 pillars. This is probably because the former are such 

 dusty and unsatisfactory things to eat, with such a 

 small proportion of body in which the nutriment and 

 taste is contained, and so large an expanse of dry 

 membranous wings with their scaly covering. In 

 this respect butterflies contrast unfavourably with 

 moths, and the latter are certainly greatly preferred by 

 lizards and especially birds. The latter have special 

 advantages in being able to pick off the wings before 

 eating the body. 



In the excessive abundance of insect-eating ani- 

 mals and the keen competition for food which takes 

 place, we see the conditions which must render the 

 acquisition of an unpleasant taste together with Warn- 

 ing Colours an exceedingly hazardous mode of defence, 

 if assumed by more than a small proportion of the 

 insects of a country. For in so great a press of com- 

 petition among the innumerable insect-eaters, we 

 may feel sure that some at least would be sufficiently 

 enterprising to make the best of food which at least 

 has the advantage of being easily seen and caught. 



The great principle of Warning Colours has de- 

 servedly taken a most important place among the 



