100 LAND-BIRDS AND GAME-BIRDS 
(b). The nest is globular, with an entrance on the side, and 
is composed principally of hanging mosses. It is usually 
placed in the woods, twenty or more feet from the ground, at 
the end of a bough of some hard-wood tree or evergreen. It 
usually contains four or five freshly laid eggs in early June, 
which average about *62 X ‘48 of an inch, and are white (or 
cream-tinted) with spots and confluent blotches of reddish- 
brown and lilac, chiefly about the crown. 
(c). The ‘‘ Blue Yellow-backs” are summer-residents through- 
Fig. 4. Blue Yellow-backed Warbler (+). 
out the eastern United States, more commonly in Northern 
Maine and New Hampshire than in Massachusetts, where 
only a few breed, chiefly, probably, in the valleys of the 
Connecticut and Nashua Rivers. Near Boston they are ex- 
tremely rare in summer, but are generally common in the sec- 
ond and third weeks of May and September, during their 
migrations, being, however, sometimes rare, and sometimes 
extremely abundant. I can in no way, I believe, better de- 
scribe their habits than by detailing the observations which I 
made upon them this spring (1875), when they were very nu- 
merous in my immediate neighborhood. They came on the eley- 
enth of May, and did not wholly disappear until the twenty- 
second of that month, after which I saw none, except a few in 
