vii DEFENCES OF INSECTS 255 



Acraeidse. They comprise many hundreds of species, 

 and inhabit all the warmer parts of the world. The 

 Heliconidae of tropical America are likewise mimicked. 

 These butterflies are generally large, conspicuously 

 and even gorgeously coloured, and their flight is feeble 

 and slow. There is not only disregard of concealment 



FIG. 51. An ant-like Spider (Synemosy no, formica) ', from Peckham. 



when on the wing, in rest no protective tints are 

 shown, 'and both surfaces of the wings are equally 

 conspicuous. The abundance of individuals is also 

 striking. These are characteristics indicating un- 

 palatability, which affords the butterflies immeasur- 

 able pre-eminence over their fellows in immunity 

 from attack, depending upon the effectiveness of 

 their colour and habits to give ready warning 

 of the circumstance. All observers speak of their 

 peculiar and often powerful pungent odour, and it has 

 been noticed that they are constantly neglected and 

 refused by birds of many kinds, and by spiders, 

 dragon-flies, lizards, and monkeys, although all these 

 greedily destroy butterflies which are much less 

 abundant, and which are swifter and less easily 

 captured. The facts point to the. possession by these 



