xv GENERAL ADAPTATIONS 321 



allies have the hind wings of an intense yellow with a silky 

 lustre, while O. Priamus and many allied species are richly 

 adorned with metallic green, deep orange, or violet-blue. 

 Papilio Ulysses of Amboyna equals in size and colour the 

 splendid blue morphos of South America ; while these latter 

 not only present us with every shade of blue on insects of 

 the largest size, but in Morpho cypris, and several allied 

 species, exhibit an intensity of colour and of metallic sheen 

 that is equal to the highest efforts of nature in this direction 

 on the caps or the gorgets of humming-birds, on the glittering 

 shields of the Epimachidae of New Guinea, or on such precious 

 gems as the emerald, the sapphire, the ruby, or the opal. 



The exquisite combinations of brilliant colour and endless 

 variety of pattern to be found among the small Lycaenidae 

 and Erycinidae of both hemispheres must be passed over ; as 

 well as the somewhat larger Catagrammas whose diversified 

 upper and under sides are a constant delight ; while the 

 vast groups of the Heliconidae and Danaidae, inedible to 

 most birds and lizards, are often rendered conspicuous by 

 bold contrasts of the purest white, yellow, or red, on a blue- 

 black ground. 



Some Extremes of Insect Coloration 



There are some examples of tropical butterflies in 

 which nature may be said to have surpassed herself, and to 

 have added a final touch to all the beauty of colour so 

 lavishly displayed elsewhere. These are to be found in a 

 few species only in both hemispheres, and are therefore the 

 more remarkable. The largest butterfly to exhibit this 

 form of colour is the Ornithoptera magellanus, from the Philip- 

 pines, whose golden-yellow wings, when viewed obliquely 

 acquire the changing hues of polished opals, quite distinct 

 from any of its numerous allies which possess the same 

 colour but with what may be termed a silky gloss. In the 

 same part of the world (the Bismarck Archipelago) there is 

 a day-flying moth (Burgena chalybeatd}^ one of the Agaristidae, 

 whose wings change from black to blue and a fiery opalescent 

 red. In tropical America there is a group of butterflies of 

 the genus Papilio, which are very abundant both in species 

 and individuals, whose velvet-black wings have a few bands 



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