412 



There are other cases in which the mimicked and the mimicker 

 belong to distinct orders of insects. Among the Lepidoptera, 

 there are " two families of day-flj'ing moths, the Sesiidee and 

 iEgeriidse, particularly remarkable in this respect from their strange 

 resemblance to stinging Hymenoptera." There are several 

 dipterous insects also so extremely like bees and wasps as often 

 quite to deceive persons who are not entomologists. In these 

 and numerous other examples that might be adduced, the 

 object of mimicry no doubt is to give immunity from attacks, 

 being probably connected with the habits of the mimicker, 

 and its dependance in some way upon the species mimicked 

 for carrying out the conditions of its existence, as in the case 

 of " flies whose larvae feed upon the larvae of bees," and who 

 by their resemblance to these last " can enter the nests unsuspected 

 to deposit their eggs." 



Mimicry shows itself also in the form and colouring of insects 

 being adapted to the surrounding conditions of the spots which 

 they inhabit. Caterpillars are often found so closely resembling 

 twigs of wood, or so exactly the colour of the leaves of the plants 

 on which they feed, as to deceive the most practised eye. If this 

 is for protection against enemies it would be curious to ascertain 

 how it would be with a succession of broods raised under artificial 

 conditions, where no enemies could come, or when brought up 

 on other food. 



In like manner the Cicindela campestris (tiger beetle), and some 

 other insects found on grassy plains, are of a bright green like the 

 grass itself. Other insects are of the colour of dead leaves, or 

 resemble small lumps of dirt. Certain moths, which are in the 

 habit of resting upon the bark of trees during the day time, can 

 hardly be distinguished from the lichens which grow close by. 

 Such might easily escape the notice of birds, which are much 

 influenced by colour in the selection of insect food. 



Nor is mimicry confined to insects. Birds inhabiting sandy 

 plains conform to the colour of the ground in the general colouring 

 of their plumage. Many animals in noi'thern climates are white, 

 or, like the hare and ptarmigan, turn white in winter, and are then 

 hardly distinguishable upon the snow. Even in our own country, 



