In the Indian Black-buck (_A. bezoartica_), which belongs to another tribe of antelopes, the male is very dark, almost black; whilst the hornless female is fawn-coloured. We have in this species, as Mr. Blyth informs me, an exactly parallel series of facts, as with the _Portax picta_, namely in the male periodically changing colour during the breeding season, in the effects of emasculation on this change, and in the young of both sexes being undistinguishable from each other. In the _Antilope niger_ the male is black, the female as well as the young being brown; in _A. sing-sing_ the male is much brighter coloured than the hornless female, and his chest and belly are blacker; in the male _A. caama_, the marks and lines which occur on various parts of the body are black instead of as in the female brown; in the brindled gnu (_A. gorgon_) “the colours of the male are nearly the same as those of the female, only deeper and of a brighter hue.”[357] Other analogous cases could be added. The Banteng bull (_Bos sondaicus_) of the Malayan archipelago is almost black, with white legs and buttocks; the cow is of a bright dun, as are the young males until about the age of three years, when they rapidly change colour. The emasculated bull reverts to the colour of the female. The female Kemas goat is paler, and the female _Capra ægagrus_ is said to be more uniformly tinted than their respective males. Deer rarely present any sexual differences in colour. Judge Caton, however, informs me that with the males of the Wapiti deer (_Cervus Canadensis_) the neck, belly, and legs are much darker than the same parts in the female; but during the winter the darker tints gradually fade away and disappear. I may here mention that Judge Caton has in his park three races of the Virginian deer, which differ slightly in colour, but the differences are almost exclusively confined to the blue winter or breeding coat; so that this case may be compared with those given in a previous chapter of closely-allied or representative species of birds which differ from each other only in their nuptial plumage.[358] The females of _Cervus paludosus_ of S. America, as well as the young of both sexes, do not possess the black stripes on the nose, and the blackish-brown line on the breast which characterise the adult males.[359] Lastly, the mature male of the beautifully coloured and spotted Axis deer is considerably darker, as I am informed by Mr. Blyth, than the female; and this hue the castrated male never acquires.