158 F. Finn — General Notes on Variation in Birds, [No. 3, 



red irides and chestnut wings, and all the rest of the plumage white, 

 where it should have been black. In the Museum is a pale dun bird of 

 this species with pale chestnut wings, and the two central tail feathers 

 decidedly fibrous and loose in texture. (Reg. No. B. 7220 procured in 

 Purneah 1871). Mr. Rutledge recently had a dun-coloured male Keel 

 {Eudynamis honorata) with fleshy-white bill and feet, but normal eyes. 

 Its plumage faded before moulting, to cream-colour, like a dun 

 pigeon's, the new feathers being strikingly darker. 



I have discussed the question of the white-headed -form of the 

 Ruff {Pavoncella ptignax leucoprora) in J.A.8.B., Ft. II, 1902, p. 82. 

 Both the living Ruffs mentioned there assumed pure white ruffs and 

 ear-tufts this year ; but one had a rufous-marked back, and the other — 

 with the white tertiaries — a grizzled one. 



C. Reversion to Normal Colour in Abnormal Varieties, 



A much-prized albino or lutino specimen, taken in that condition, 

 often disappoints its owner by moulting out into the normal colour. 

 Mr. W. Rutledge tells me that this is always liable to happen unless 

 the individual has pink eyes or an abnormally white bill or feet. I 

 have seen entire or partial resumption of the normal colour in two 

 House-Mynahs {Acridotheres tristis), and a Babbler (^Grateropus canorus) 

 in his possession. (See paper on Variation above quoted, J.A.S.B. 1902, 

 also Bateson, Materials for the Study of Variation, p. 43, foot note 2). 



Pallid specimens are also liable to revert in this way. A male 

 cream-coloured sparrow I recently obtained put out new feathers of a 

 nearly normal colour, and I have seen a skin of the House-Mynah in 

 the same condition. The grey Bengal Bulbul above alluded to, however, 

 has never reverted ; its bill and feet are normally black, as were those 

 of the two grey Jackdaws mentioned with it. 



The same phenomenon has occurred in the case of melanism. A 

 Bullfinch {PyrrJiula pyrrhula) found as a black nestling in an otherwise 

 normal brood, attained on moulting ordinary female plumage (Howard 

 Saunders, Manual of British Birds, p. 188, ed. 1889). 



It seems to me that such facts as these furnish a simple explana- 

 tion of the case of those Herons which are white only in youth. 



Variations in Relation of Immature to Adult Plumage. 



Darwin gives several cases of this on BIyth's authority, and I can 

 add a few myself. 



The skin of a young Crow-Pheasant (Centropus sinensis) in the 

 Indian Museum (Reg. No. 11265 from Bhowra) already shows in per- 



1 



