3a4 SYLVIADA. 
parent birds in the colour of their plumage; but in the 
autumn after their first moult the whole of the under 
surface of the body is more decidedly yellow than the 
same parts in the parent birds at the same season, and this 
yellow colour is retained to some extent till after their 
re-appearance here in the following spring, so that it is 
not difficult to select the birds of the previous year from 
those which are older. 
The vignette below represents the nest of the Wood 
Warbler, which resembles also that of the Willow Wavr- 
bler, but there is this distinction in the materials, which is, 
I believe, constant ; I have never seen a nest of the Wood 
Warbler with any feathers in it, or the nest of the Willow 
Warbler without feathers. 
