188 Moustey, Breeding of the Black-throated Blue Warbler. eer 
The finding of most warblers’ nests is not an easy matter at any 
time, but one is generally aided to some extent if the birds can be 
watched at migration time, as some indication is then often gathered 
of where a certain species is likely to nest by always finding it near 
or about the same spot in the woods. ‘This missing, then, of the 
spring migration as will be readily understood was a great draw- 
back, but fortunately I had found the three species already named 
during the summer of 1915, frequenting a large wood not far from 
my house, which consisted for the most part of a mixture of such 
trees as maple, beech, fir, pine and hemlock with nice open spaces 
in many parts where young maple saplings and others had obtained 
a height varying from one to six feet or more. It was to this wood 
therefore that I repaired on June 14 with the full determination of 
thoroughly exploring the ground where I had located a pair of 
Black-throated Blue Warblers on June 23, 1915, but had failed to 
find any trace of their nest. Hardly had I reached the spot and 
started to search, when in the forks of a little maple sapling just 
three feet above the ground (and only fifty yards from the spot 
where I had flushed the female in the previous year) I came upon a 
beautiful nest, which was different from any warbler’s I had ever 
found before, and which from its construction I took to be the one 
I was in search of. 
It was not what one might describe as entirely typical of the 
species, for the outside construction lacked the rotten or pithy 
wood, which is so characteristic of these birds, but in other respects 
it conformed to standard requirements, as not only was it large and 
bulky, but the sides were thick walled, being composed for the upper 
part of woven cedar or grape vine bark, whilst the lower portion 
was of white birch bark, the lining consisting of slender, red, hair- 
like rootlets (exactly the same as used by the Magnolia here) and 
some hair. 
The dimensions were as follows, viz: outside diameter three and 
a fourth inches, inside one and three-fourths inches; outside depth 
four and three-fourths inches, inside one and one-half inches; and 
at the time of finding was empty, but apparently quite finished. 
On visiting it the following day about eleven o’clock it contained 
one egg, and for the next three days (always before the above men- 
tioned time) an extra one was laid until the full set of four was 
