TAILED AND UNTAILED FEMALES. 563 



the male. Respecting this peculiarity, Mr. Wallace, in his 

 " Eastern Archipelago," makes the following remarks : — 



" The first is the handsome Papilio Memnon, a splendid 

 Butterfly of a deep black colour, dotted over with lines and 

 groups of scales of a clear ashy blue. Its wings are five inches 

 in expanse, and the hind wings are rounded, with scalloped 

 edges. This applies to the males ; but the females are very dif- 

 ferent, and vary so much that they were once supposed to form 

 several distinct species. They may be divided into two groups 

 — those which resemble the male in shape, and those which 

 differ entirely from him in the outline of the wings. 



" The first vary much in colour, being often nearly white, 

 with dusky yellow and red markings ; but such differences often 

 occur in Butterflies. The second group are much more extra- 

 ordinary, and would never be supposed to be the same insect, 

 since the hind wings are lengthened out into large spoon- 

 shaped tails, no rudiment of which is ever to be perceived in 

 the males or in the ordinary form of females. These tailed 

 females are never of the dark and blue-glossed tints which pre- 

 vail in the male and often occur in the females of the same 

 form, but are invariably ornamented with stripes and patches of 

 white or buff, occupying the larger part of the surface of the 

 hind wings. This peculiarity of colouring led me to discover 

 that this extraordinary female closely resembles (when flying) 

 another Butterfly of the same genus but of a different group 

 (Papilio Coon), and that we have here a case of mimicry similar 

 to those so well illustrated and explained by Mr. Bates. 



" That the resemblance is not accidental is sufficiently proved 

 by the fact that in the North of India, where Papilio Coon is 

 replaced by an allied form {Papilio Doubleclayi) having red spots 

 in place of yellow, a closely allied species or variety of Papilio 

 Memnon (P. androgens) has the tailed female also red spotted. 

 The use and reason of this resemblance appears to be that the 

 Butterflies imitated belong to a section of the genus Papilio, 

 which, from some cause or other, are not attacked by birds, and 

 by so closely resembling these in form and colour, the female of 

 Memnon and its ally also escape persecution. Two other species 

 of this same section (Papilio Antiplms and Papilio Polyphontes) 

 are so closely imitated by two female forms of Papilio Theseus 

 (which comes in the same section with Memnon) that they com- 



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