COLORATION loi 



tention here made that the young of the Anatidse were 

 originally more completely striped, and therein agree 

 with what obtained apparently everywhere among the 

 birds in more remote times. These links with the past 

 are furnished by the geese of the genera Cereopsis and 

 Cloephaga, and in the ducks of the genus Merga'netta. 

 Herein, as may be seen in the appended photograph of a 

 nestling of the Cereopsis Goose, a median and two lateral 

 stripes are present, making a close approximation to what 

 obtains among the gallinaceous birds. 



Nestling birds of the nidicolous or helpless types are aU, 

 when they have any covering at all, uniformly coloured, 

 with the single exception of the young osprey, which is 

 longitudinally striped. This fact is not only an extremely 

 interesting, but also an extremely important one ; for it 

 justifies the inference that when several members of any 

 given group afford a contrast with the remaining members 

 of that group in possessing some character which we have 

 reason to regard as a survival from past times, we may 

 regard those individuals which lack this index as members 

 which have lost that character. 



The osprey, the upland goose, and the ducks of the 

 genus Merganetta are illustrations of the truth of this. 

 The nestlings, which exhibit striped liveries in varying 

 degrees of perfection, are valuable indices which indicate 

 the process of disintegration, and at the same time the 

 evolution of new characters. The osprey is not a common 

 bird ; it might well have become exterminated by now, 

 without leaving a record of the ancient livery worn by 

 its young, in which case we should have assumed that 

 the raptorial birds must be left out of the account in so 

 far as striped liveries are concerned. 



Nestling birds, then, in their coloration display three 



