PROTECTIVE COLORATION. 97 



mode of life may encourage the growth of these vegetable 

 parasites, which could uot gain a footing upon the bodies of 

 more active animals. 



Protective Coloration the Prevailing Device among 

 Leaf-feeding Caterpillars. 



The majority of the caterpillars of the Lepidoptera are pro- 

 tectively coloured ; it is the rule, for instance, with the extensive 

 families of the Noctuae, the Geometry and the Tortrices ; there 

 are exceptions to this rule, as to every rule: for example, the 

 larvae of the Acronyctides, the Dagger moth and its allies, 

 including the "Merveil du Jour "; these larva? are usually hairy 

 and brightly coloured; this exception, however, may possibly 

 be explained as due to affinity : the larva? closely resemble the 

 brightly or at least conspicuously coloured and hairy larva? of 

 the Bombyces : and this group of Noctuae are sometimes classed 

 apart from the rest as Bombycoidea, a term which gives ex- 

 pression to this view. On the w r hole, it seems more profitable 

 to a caterpillar to adopt protective resemblance to its sur- 

 roundings as a means of escaping its foes ; at any rate, this 

 is what actually occurs. " The main purpose in life of a 

 caterpillar," says Mr. Scudder, " next to feeding, is not to be 

 seen."" Even some larva? which are commonly regarded as 

 exhibiting warning colours are by no means conspicuous r 

 particularly if they feed among flowers, or upon low-growing 

 plants in situations where there is a varied vegetation and 

 abundance of flowers. Larva?, as well as other animals which 

 have not a very marked protective resemblance to any special 

 object, or have not a colour which is in general harmony with 

 the environment, are nevertheless by no means invariably 

 conspicuous. 



