114 
JER FALCON. 
In the young of the year, the colour* is mostly 
of a dull brown, little white being at all visible. 
As they grow in age, the white increases, the dark 
parts of the feathers narrowing to a central blotch ; 
and in the mature birds white becomes the pre- 
dominating colour : some birds are nearly white 
altogether, but, as hinted at by Dr Richardson, 
this state may be a variation only sometimes 
occurring, specimens in this plumage being cer- 
tainly rare. Our next species is 
Richardson, No. 2, c. 29. 
