20 THE ZOOLOGIST. 



phenomenon. The wing-scales are grooved zigzag, it has been 

 said, and the opposite sides of the grooves are coloured blue and 

 purple, so as to look different when looked at two ways ; or 

 their surface is striated or beaded, and when the scratches on a 

 surface run close the mother-of-pearl colours always appear — 

 that is to say, the strange iridescence is shot from the surface of 

 the scales. I have in my hands, thanks to the kindness of a 

 dealer, a perfectly lovely "purple emperor " from the forests of 

 •Peru ; it is brown and orange, sashed with an emerald edged 

 white ribbon ; and I notice that when I hold it head upwards the 

 wings are flaked with silky purple, and the white band has 

 become orange ; but when I hold it head downwards this lustre 

 is gone. Hence I conceive it arises from the even rows of 

 rounded scales being set on edge so as to cast behind them broad 

 lines of purple shadow. So the wings of the other Apaturas 

 kindle when slant to the light. The tawny clijtie, common in 

 forest clearings and distributed from Europe to Japan, is wont 

 to assume a delicate strawberry hue, and our own iris dons its 

 marine blue. I have often looked at the windows of a dress- 

 shop, but I never saw anything so enchanting as this male 

 costume. Admirers of butterflies are most overcome with the 

 flashing splendour of Apatura lavinia and Moiyho cypris, in- 

 habitants of the forests of Tropical America. 



Male butterflies, when not lovely, are sometimes perfumed ; 

 the white or yellow Catopsilias of the Old World, to which some 

 unite the Calliclryas of the New, expand scent-fans from under 

 their fore wings, in connection with which there is a chalky spot 

 of different scaling on the hinder. Certain only of the genus 

 Colias — as our " clouded yellow," C. edusa — have the spot and 

 not the scent-tuft ; there is a patch on the wings of Hippai-chia 

 semele, that lowers its fore wings and seeks concealment on the 

 heather. No doubt a fragrance of jasmine diffused on the warm 

 air causes the little winged pilgrims to leave the east of Ceylon 

 on the setting in of the north-east monsoon, or rainy season, 

 and crossing the island to travel along the sea-coast in company 

 until they reach the northern extremity, where they are said to 

 cross the strait to the continent of India. Major Neville 

 Maunders, who has investigated the migration of Catopsilia 

 pyranthe, says : — '* A migratory flight was in full swing on the 



