MIMETIC RESEMBLANCES 



size, and the colours of the upper surface of its wings, 

 resemble those of the CalUthea Leprieurii, already de- 

 scribed, namely, dark blue, with a broad silvery-green 

 border. When it settles on leaves of trees, fifteen or 

 twenty feet from the ground, it closes its wings and 

 then exhibits a row of brilliant pale-blue eye-like spots 

 with white pupils, which adorns their under surface. Its 

 flight is exceedingly swift, but when at rest it is not 

 easily made to budge . from its place ; or if driven off, 

 returns soon after to the same spot. Its superficial 

 resemblance to Callithea Leprieurii, which is a very 

 abundant species in the same locality, is very close. 

 The likeness might be considered a mere accidental 

 coincidence, especially as it refers chiefly to the upper 

 surface of the wings, if similar parallel resemblances 

 did not occur between other species of the same two 

 genera. Thus, on the Upper Amazons, another totally 

 distinct kind of Agrias mimicks still more closely another 

 Callithea ; both insects being peculiar to the district 

 where they are found flying together. Resemblances 

 of this nature are very numerous in the insect world. 

 I was much struck with them in the course of my travels, 

 especially when , on removing from one district to another, 

 local varieties of certain species were found accompanied 

 by local varieties of the species which counterfeited 

 them in the former locality, under a dress changed to 

 correspond with the altered liveries of the species they 

 mimicked. One cannot help concluding these imitations 

 to be intentional, and that nature has some motive in 

 their production. In many cases, the reason of the 

 imitation is sufliciently plain. For instance, when a fly 

 or parasitic bee has a deceptive resemblance to the species 

 of working bee, in whose nest it deposits the egg it has 

 otherwise no means of providing for, or when a leaping- 

 spider, as it crouches in the axil of a leaf waiting for its 

 prey, presents an exact imitation of a flower-bud ; it is 

 evident that the benefit of the imitating species is the 

 object bad in view. When, however, an insect mimicks 

 another species of its own order where predaceous or 

 parasitic habits are out of the question, it is not so easy 

 to divine the precise motive of the adaptation. We may 

 be sure, nevertheless, that one of the two is assimilated 

 in external appearance to the other for some purpose 

 useful — perhaps of life and death importance — to the 



