TERRIFYING MARKS AND ATTITUDE 221 



moors, have large eye-like markings on the hind wings, 

 which are concealed by the fore wings when the moth 

 is at rest, but under certain circumstances are exposed. 

 One of these, a comparatively dull coloured species, was 

 offered to my pet monkeys on Bugalla Island. The 

 following account is quoted from my article in Bedrock.^ 



" The moth was a large yellow species with well marked 

 eye -like spots on the hind wings. When alarmed it bent 

 the body ventrally into a strong curve, and held the wings 

 in a very curious and unusual fashion — almost upright, 

 with the upper surface directed forwards so that the 

 eye-like markings were extremely conspicuous ; indeed, 

 the attitude was obviously intended to display those 

 * eyes.' The moth thus looked curiously weird and un- 

 mothlike, and the monkeys were afraid even to touch it. 

 It was not merely the size of which they were afraid, 

 because they caught and readily devoured large and 

 protectively coloured moths (Sphingomorpha) often found 

 about the house." 



Finally, it must not be concluded that all bright colours 

 in insects are aposematic. In the case of butterflies both 

 surfaces of the wings must be considered ; only the lower 

 surface is displayed when the insect is at rest and likely 

 to be caught unawares, for when on the wing a butterfly 

 is alert and can escape by flight. Consequently a large 

 number of species, the upper surfaces of whose wings are 

 vividly coloured, are really procryptic if the lower surfaces 

 be considered. I need only mention our English " Red 

 Admiral," and the famous leaf butterflies of Asia and 

 Africa [Kallima). 



Darwin concluded that the colours of butterflies owed 

 much to Sexual Selection, and those who have seen butter- 

 flies courting will probably agree that vision does enter 

 into the question. I have seen a male Bapilio dardanus 



* " Notes on the Struggle for Existence in Tropical Africa," Bedrock, 

 1913, vol. ii, p. 366. 



