446 BIRDS OF INDIA. 



The young femalt^ has the same, without the long tail In a still 

 younger state, the throat, breast, upper part of abdomen, and the 

 flanks, are ashy. 



Bill and eyelids cobalt-blue ; legs and feet pale lavender-blue ; 

 irides deep brown. 



Length to end of outer tail-feathers, about 9 inches ; wing 3^;% ; 

 tail Ah to 5 inches; central tail-feathers sometimes 15 or 16 

 inches ; bill at front y"y , or nearly f ; tarsus y'^j. 



A complete account of the changes of plumage of this and the 

 next species is still a desideratum. In the above description 

 I have given the generally received account of the phases of 

 pkunage ; but at what age the chesnut bird becomes white 

 is not precisely ascertained. Nestlings that I liave seen have' 

 the head and crest, which latter is not much developed, ashy- 

 black, and the chesnut dull. At the first moult, the plumage 

 described as that of the ' still younger state ' is probably assumed ; 

 next year the bright cliesnut ; and at the breeding season of the third 

 year, the feathers probably begin to change to Avhite, and at the 

 autumnal moult most probably become entirely v/hite. Some obser- 

 vers have suggested that the white livery is only the nuptial plu- 

 mage, and that the chesnut plumage is re-assumed at the next 

 moult ; but I have not seen any specimens warranting that surmise, 

 and jier contra have seen young feathers perfectly white, so that that 

 hypothesis is untenable. The change of coloration through some 

 organic chemical process, whicli is w^ell known to effect a change 

 especially in the tips of the feathers of many birds during the 

 breeding season, also appears always to begin first in the substance of 

 the feather itself, and generally shews itself first in the quills or rec- 

 trices. Many interesting specimens exhibiting this change are in the 

 Museum As. Soc, Calcutta. I figured a bird in a state of change in 

 my ' Illustrations of Indian Ornithology,' as in some of the later 

 publications on Indian birds,* it had been asserted that the chesnut 

 and white-colored individuals Avere distinct in species; but I see that 

 Levaillant, who has figured this bird, pi. 144 to 146 of his Ois. de 

 VJfnque,h.u.d previously given drawings of some highly mottled and 



* Svkes's Catalogue, 



