significance of icing -marking b. lOB 



spots {A. paphia), partly to an alteration in the general 

 ground colour, which in these females shows an infusion 

 of a dull olive of various degrees of intensity into the 

 bright tawny ground colour characteristic of the male 

 {A. papliia, aglaia, adippe, &c.). As is well known, a 

 *' melanic " variety of the female of the first-named species 

 sometimes turns up, in which the whole ground colour is 

 of a deep dusky olive, no trace of the usual tawny colour 

 being visible. The females of some species of Argynnis 

 are normally as completely destitute of the usual bright 

 ground colour as these occasional melanic females, the 

 prevailing tone in such cases being, similarly, a deep 

 dusky olive or blue-green ; the bluish tinge prevailing, 

 e.g., in A. diana, the greenish in A. sagana. In other 

 species we see this dark blue or green ground colour 

 confined to a particular area of the wing, e.g., the tip of 

 the fore wing and border of both wings in A. niphe ? , 

 the border of the hind wing in A. niphe ^ ; the posterior 

 and inner half of the hind wing in A. pandora and 

 A. childreni ? , the border at the anal angle in the hind 

 wing of A. childreni <? . It is significant that in all 

 these cases, if the bluish or greenish ground colour is 

 visible in only one sex, that sex is the female ; if it is 

 visible in both sexes, it prevails to a much greater extent 

 in the female than in the male. 



Prof. Meldola (in Weismann, op. cit., vol. i., p. 8, note) 

 quotes Mr. Wallace* as holding that the dark colour of 

 many female butterflies is a character acquired for pur- 

 poses of protection ; but the facts to which I have called 

 attention, more especially the occasional occurrence in at 

 least one brown Argi/nnis of a melanic variety so closely 

 resembling in coloration the normal female of other 

 species, and the presence of traces of the same dark ground 

 colour in some of the male Argynnids, would seem rather 

 to point to the conclusion that at any rate in this group the 

 dark blue or green is ancestral ; preserved, no doubt, in 

 many instances for purj^oses of protection, but in the first 

 place deriving its origin from the progenitors of the race. 



* ' Contributions to the Theory of Natural Selection,' 1870, 

 pp. 11'2 — 114. In the same author's ' Darwinism,' 1889, pp. 276, 

 277, the analogous sober coloration of the female in many species 

 of birds is considered to be an ancestral rather than an acquired 

 feature. I am not sure that Wallace's words as cited by Professor 

 Meldola necessarily imply that the same may not be the case with 

 butterflies. 



