580 



Dr. F. A. Bixeymrejily to Mr, G. A. K. Marghall 



In stating that " the crux of the whole argument lies 

 in the assumption that white colouring is abnormal in 

 He! ironiiis and must therefore be duo to Pierine influence" 

 (p. 114), Mr. Marshall is labouring under a similar mis- 

 apprehension to that which led him to attribute to me the 

 view that the existence of red spots in Fapilio originated 

 in mimicry of tlie Pierines. I have shown that my ex- 

 pressed view was the contrary of this, and that I regarded 

 and still regard the original red spots in both groups as 

 atibrding material for an assimilative process of which 

 there remain in existence many traces. In exactly the 

 same way I look upon the occasional presence of white 

 patches and bands in Hdiconius as the raw material from 

 which a resemblance to the broad white areas of the usual 

 Pierine aspect has been in certain species manufactured. 

 Any one who has not realised how much like a Pierine a 

 Heliconius can be made to look, should compare the Icuce 

 form of H. sapho with the female of the form of P. locusta 

 known as noctipennis. 



The suggested diaposematic resemblance hetiveen the tioo 

 Eastern Pierines Huphina corva and Ixias baliensis $ . 



It would, I think, hardly be inferred from Mr. Marshall's 

 account of this example that nearly all the points which 

 he raises had already been taken into account by me and 

 allowed due weight in my paper which he quotes. Thus 

 the difference between the under sides of the Huphina 

 and the Ixias is in that paper both mentioned and 

 specially figured, while an explanation is offered which 

 is probably valid in several similar cases (Trans. Ent. Soc. 

 Lond., 1906, p. 522). The fact that the dark border of 

 the hind-wing is better defined in the male than in the 

 female Huphina is of course perfectly apparent in my 

 figures {Ibid., PI. XXXI). These show that although in 

 this particular respect the male has the advantage, the 

 female is still on the whole the better mimic. They also 

 show that the "heavy black bar across the cell of the fore- 

 wing " is not " entirely absent " from the male, as Mr. 

 Marshall alleges, but present in the corresponding position 

 to that which it takes in the female, though of course 

 in the former sex it has not reached so hmh. a stage of 

 development. 



The facts as to the geographical distribution of the two 

 species were carefully noted by me {loc. cit., p. 523), as 



