OF EASTERN PENNSYLVANIA. 1 05 



of three and a quarter inches, and a height of one 

 and a half. -The cavity is two inches in diameter 

 and one and a half in height. 



The eggs are usually four in number, with 

 numerous dots and blotches of purplish-brown 

 upon a white or flesh-colored background, scat- 

 tered over the entire surface, but mainly about the 

 larger end. 



Dcndrceca cczrulescens, Baird. 



The Black-throated Blue Warbler as this 

 species is called in unscientific language, is neither 

 very rare nor very abundant. It arrives early in 

 May, and retires to its breeding-quarters not 

 earlier than the 27th of this month, its stay being 

 prolonged a trifle over three weeks. Its habits of 

 feeding are solitary, mostly arboreal, and* mainly 

 restricted to dense forests, where among the 

 smaller trees and bushes it gleans a scanty sub- 

 sistence. When driven by necessity to the taller 

 trees, unlike its near congener whose history we 

 have just detailed, it never visits the topmost 

 boughs, but restricts itself exclusively to the 

 lower branches. 



As the season advances, attracted by the blos- 

 soms of the apple and cherry, it retires from 

 woodland scenery and seeks the haunts of man, 

 where it fares more luxuriously, and with less 

 outlay of strength. There is now a marked 

 change in its demeanor. Confidence and courage 

 have given place to suspicion and timidity. 



