THROUGH THE YEAR 99 



any one can now doubt that the lovely colouring, 

 the pennants and the lyres of birds are not the work 

 of sexual selection, or the refined and fantastic 

 beauties of butterflies and other insects. Denying 

 sexual selection in these, we must either fall back 

 on the old notion that they are fashioned expressly 

 for the pleasure of human beings, or we must say 

 there is no explaining them. 



In a sale of a great collection of butterflies, I saw 

 three sets of exotic butterflies in which insect orna- 

 ment was seen at its finest. One set included differ- 

 ent species of the Morpho butterflies, such as Mene- 

 laus, Hercules and Cypris. The chief feature of this 

 class is the light shot iris which covers all the upper 

 sides of the wings. It is colour produced just as is 

 that on the wings of our own purple emperor butter- 

 fly, save that the blue is lighter and more vivid 

 one need not view the Morpho butterfly so much at 

 a particular angle to catch the colour as with the 

 emperor. It is interference colour. It has nothing 

 to do with pigment, but is made by an arrangement 

 of the scales of the wing which splits up the light 

 rays. 



The splendour of these Morpho butterflies is 

 almost wholly in the colour. But it is not so with 

 the wondrous bird- winged butterflies. Two of these 

 surpass all others I have seen in collections 

 Ornithopteron victorioe and Ornithopteron para- 

 diseum. The male bird- winged butterfly of paradise 

 has a swallow-tail, ending in a tip almost as fine as 

 an insect's antenna. These bird-winged butterflies 



