OF EASTERN PENNSYLVANIA. 223 



diameter and two and a half in height, and is placed 

 from ten to fifteen feet above the earth. 



The young are objects of the tenderest solicitude 

 upon the part of the parents. They are fed upon 

 the dipterous and lepidopterous insects mentioned 

 above. Between the ages of 1 1 and 1 2 days they 

 quit the nest, but are still fed by the parents for 

 a week longer, when they are compelled to provide 

 their own subsistence. 



This species is chiefly insectivorous, and subsists 

 mostly upon insects, with the exception of a few 

 berries as those of the Juniperus Virgiana, until 

 its departure for Central America, and the United 

 States of Columbia in South America, during the 

 last week of September. In the fall its food con- 

 sists of the larvae of Colias philodice, Orgya Leucos- 

 tigma, Clisiocampa Americana, and many of the 

 Phalcenidce and Uineidtf. 



The eggs are white, with a slightly-roseate tinge 

 when fresh, and are marked with blotches of red- 

 dish-brown, more or less. The average measure- 

 ment is .83 by .64 inches. 



Vireo solitarius, V i e i 1 1 . 



The Blue-headed Vireo arrives usually about 

 the 1 5th of April, and, occasionally, as late as the 

 beginning of May. It prefers most generally soli- 

 tary situations, and unlike Vireo olivaceus, delights 

 to nidificate on the confines of dense forests, and 

 along roads where travel is of rare occurrence, Its 

 favorite trees for building-purposes are Juniperus 



