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Show 250 MR. G. E. DOBSON ON SECONDARY SEXUAL [Mar. 4, to a distinct species, R. perniger, Hodgs.; others are black, sprinkled with silvery grey, and must therefore, according to the same authority, be relegated to a distinct species. But the closest examination fails to detect any structural difference other than sexual between these specimens from Darjeeling. The "reddish leaf-nosed Bat" of Fitzinger, R. eudouxii, Laplace, from the Philippine Islands, is most probably the male R. luctus, its brighter colour depending on locality, and perhaps, in a less degree, on season. In the Journ. As. Soc. Beng. vol. xii. p. 220, I have shown the identity of Phyllorhina fulva, Gray, with P. murina, Gray, and P. cineracea, Blyth, and have expressed m y belief that P. atra et atrata, which differ from P. fulva also only in the colour of the fur, are referable to the same species. Later, in the Proc. As. Soc. Beng., Aug. 1871, p. 155, I have remarked that the rich golden hue of the fur of some specimens of P. fulva depends most probably on sex and season, seeing that, of several specimens possessing this golden colour examined by me, all were females and each contained a more or less developed foetus. In the same paper I have adduced evidence which now satisfies me that this golden colour is only possessed by the females, and by them only under certain circumstances, as when in the pregnant condition. Mr. Blyth, who, in common with other zoologists, regarded the golden-coloured specimens of P. fulva as representing a species distinct from the white and black specimens, writes as follows :- " This is perhaps the most vividly coloured of the whole class of Mammalia; at least I know of no species which can at all compete with it for brilliancy of hue. The colour of the fur is here alluded to ; for that of the naked skin of the Mandrill and of certain Cerco-pltheci can scarcely be surpassed. The general tint of the fur is splendidly bright ferruginous, that of the upper parts being slightly tipped with a darker shade ; membranes dusky." To this Mr. Blyth adds:-"Inhabits Southern India, where very rare"*. The comparative rarity of the golden- coloured specimens is easily explained when we know that this colour is only possessed by the females of P. fulva, and by them only under certain conditions". I believe the same change occurs in the breeding-season among the females of Nycticeius temminckii, Horsf., the commonest Bat about Calcutta. The usual colour of this Bat is pale straw-colour on the under surface, sometimes almost white. This colour 1 have observed in male and female specimens from all parts of India; but in females obtained in the months of March and April I found the prevailing hue to be rich saffron-colour, exceeding that of the Canary bird. Among the Frugivorous Bats the same rule appears to hold good, that the females are always darker in colour than the males of the same age. This I have constantly observed in Pteropus medius, Temm. Also in a Pteropus from the Andamans f and Nicobars the females * Journ. As. Soc. Beng. vol. xiii. p. 489. t Distinguished by tbe form and size of its ears from Pt. medius and other allied species, probably Pt. nicobaricus, Schriezer, Novara Expedition. The first |