204 THE COLOURATION OF INSECTS 



But the foUomng example i.s more probably anticryptic. 



On Nsadzi Isle there is a fine sandy beach frequented 

 by Egyptian geese and wading birds, whose droppings 

 attract little blue butterflies and Skippers, which settle 

 on them to feed. I found one day, sitting on a patch 

 of bird dropjDing and sucking the juices of a captured 

 Lycaenid butterfly, a small flat bug, Mononyx grandicollis, 

 of the group Cryptocerata, whose tints accorded admirably 

 with those of the dropping on the wet sand. 



Hitherto we have been considering examples of insects 

 concealed by their resemblance to their surroundings. 

 But a large number of species are extremely conspicuous, 

 and many of them seem to court attention, I use these 

 words dehberately, and as a result of several years' obser- 

 vation in the field. But a school has arisen in America 

 following the teaching of the distinguished artist-naturaHst 

 Thayer,! which believes that all creatures are concealed 

 by their resemblance to their surroundings, no matter 

 how brilliant and startling their colouration appears to 

 be in the cabinet. Many butterflies are supposed to be 

 like the flowery part of their surroundings. ^ In some 

 cases this is certainly true ; the greenish-yellow Pierines 

 of genus Terias, when feeding from yellow flowers among 

 herbage, are very well in harmony with them, and quite 

 well concealed. So also the under surfaces of the wings 

 of other Pierines tone very well mth flowers or grasses ; 

 our own orange-tip is a well known instance. 



But these are all what a Darwinian calls procryptic, 

 so that here there is no difference between him and the 

 follower of Thayer. When the species which Poulton 

 called Aposematic (i.e. with " warning " colouration) are 

 considered, it is difficult to accept the doctrine that they 

 really harmonize with their environment or with any part 

 of it. Take for example the typical habitat on the islands 



* See Concealing Coloration in the A7%imal Kingdom. 

 2 Loc. cit., pp. 228-229. New edition, 1918. 



