112 OCCASIONAL PAPERS. 



' Helice. There are several specimens on the table, 

 varying in size and markings. Now a few years ago 

 Helice was particularly rare ; I well remember the 

 capture of my first, ten years ago. I was driving out 

 with a friend through Acrise when I believed I saw 

 Helice settle on a flower by the road side. My 

 friend kindly stopped while I went back, Helice as 

 kindly waited to be caught, and I came back with it 

 in my box. It was a red letter day with me. But 

 last year it was not much thought of ; it came into 

 our gardens ; Mr. Austen took 78. I suppose there 

 is scarcely a cabinet now without it. Now if Helice 

 occurred in a separate country and away from Edusa, 

 there is little doubt that it would be set down as a 

 different species altogether, and not as a mere variety 

 like a white hyacinth. There are many species that 

 differ far less than these two. Stay ; there is one 

 fact against making Helice a species every specimen 

 is a female ; there are no white varieties of the males. 

 You will agree with me that this is a very curious 

 fact. Why should the female Edusa occasionally be 

 white instead of yellow ? 



" And yet more why " 



Why should the male never undergo such a change ? 

 Again I have no reply, only a suggestion. But first 

 let me state that the occurrence of two forms of 

 females with only one of males is not restricted to 

 Edusa. It is known to exist with several other 

 butterflies. Mr. Wallace, in his book on the Malay 

 Archipelago, alludes to a very striking instance in 

 Papilio Memnon, a large handsome butterfly of a 

 deep black colour with various coloured markings, 

 measuring five inches in expanse of wing. There 



