[107] [Figures of a remarkable case of gynandromorphism in a butterfly (_Cirrochroa Aoris_, Doubl.) have recently been published by Prof. Westwood (Trans. Ent. Soc. 1880, p. 113). On the right fore- and hind-wings of a male specimen there are patches of female colouring, thus bearing out in a very striking manner the above views concerning the non-fusibility of characters (in this case sexual) which have been long fixed. Complete (_i.e._ half-and-half) gynandromorphism is not uncommon in butterflies. R.M.] [108] [I have long held the opinion that the di- and trimorphism displayed by certain butterflies has originated through polymorphism from ordinary variability. I will not here enter into details, but will only cite a few instances indicating the general direction of the arguments. The phenomenon to which I refer is that so ably treated of by Mr. A. R. Wallace (see Part I., p. 32, note 20) and others. One male has often two or more distinctly coloured females, and in such cases one form of the female generally resembles the male in colour. Cases of polymorphic _mimetic_ females may for the present be excluded, in order to reduce the argument to its greatest simplicity. Thus, in the case of native species, _Colias Edusa_ has two females, one having the orange ground-colour of the male, and the other the well-known light form, var. _Helice_. So, also, _Argynnis Paphia_ has a normal female and the dark melanic form var. _Valezina_. Numerous other cases might be mentioned among exotic species; and, looking at the phenomenon as a whole, it is seen to be one of _gradation_. For instance, our common “Blues” (_Plebeius Icarus_, _P. Thetis_, &c.) have females showing a complete gradation between the ordinary blue male and the brown female coloration. In a large number of specimens of _Callosune Eupompe_ in my cabinet, collected in Arabia by the late J. K. Lord, there is a completely graduated series of females, varying from individuals having the scarlet tips of the fore-wings as strongly developed as in the males, to specimens without a trace of such colouring; and the same is the case with other species of this and allied genera. In such instances it is only necessary for the intermediate female forms to become extinct, in order to have true cases of dimorphism. It is significant that in 1877, when _Colias Edusa_ appeared in this country in such extraordinary profusion, large numbers of _intermediate forms_ were captured, these forming an uninterrupted series connecting the normal female and the var. _Helice_. R.M.] [109] [Many of our best describers of caterpillars, such as the late Edward Newman, Messrs. Hellins and Buckler, &c., have described the various forms of numerous polymorphic species, but not from the point of view of the comparative morphology and ontogeny of the markings. R.M.] [110] [In Butler’s revision both these species are placed in the genus _Hemaris_. R.M.]