NESTING OF THE BLUE-HEADED GEEENLET 513 



described by Dr. Brewer, whose excellent opportunities for ex- 

 amination of these structures have been fully utilized in his 

 contribution to the history of the species. I extract his inter- 

 esting account in full : — 



" Seven nests of this species, found in Lynn and Hingham, 

 Mass., exhibit peculiarities of structure substantially identical. 

 In comparison with the nests of other Yireos, they are all 

 loosely constructed, and seem to be not so securely fastened to 

 the twigs from which they are suspended. One of these nests, 

 typical of the general character, obtained in Lynn, May 27, 

 1859, by Mr. George O. Welch, was suspended from the 

 branches of a young oak, about twelve feet from the ground. 

 The external depth of this nest was only two and a half inches, 

 the diameter three and a quarter, and its cavity one and three 

 quarters deep, and two inches wide at the rim. It was con- 

 structed externally of strips of yellow and of gray birch-bark, 

 intermingled with bits of wood and dry grassas. The external 

 portion was quite loosely put together, but was lined, in a more 

 compact manner, with dry leaves of the white pine, arranged 

 in layers. Another nest, found in Hingham, was but two feet 

 from the ground, on a branch of a hickory sapling. In its 

 general structure it was the same, only differing in shape, being 

 made to conform to its position, and being twice as loug as it 

 was broad. It contained four young, when found, about the 

 10th of June. One nest alone, built in a bush in Lynn, exhibits 

 an average degree of compactness in its external structure. 

 This is largely composed of cocoons, which are woven together 

 into a somewhat homogeneous and cloth-like substance. With- 

 in, decayed stems of grasses take the place of the usual pine- 

 needles. In the summer of 1870 a pair built their nest in a 

 dwarf pear-tree, within a few rods of my house. They were at 

 first very shy and would not permit themselves to be seen at 

 their work, and suspended all labor when any one was occupied 

 near their chosen tree. Soon after the construction of the nest 

 twoCowbird's eggs were deposited, which I removed, although 

 the female only laid two of her own before she began to sit 

 upon them. By this time she became more familiar, and would 

 not leave her nest unless I attempted to lay hands upon her. 

 She made no complaint in the manner of the White-eyed, nor 

 sought to attack like the Yellow-throated, but kept within a 

 few feet, and watched me with eager eyes, until I left her. 

 33 B c 



