NATURAL SCIENCES OF PHILADELPHIA. 101 



have often observed him bringing food to the female while thus 

 engaged. When the young have developed from the egg, both 

 parents are extremely sedulous in their attention to them until 

 they have attained their feathered stage, when the mother seems 

 to hand them over to the father to initiate into the mysteries of 

 aerial navigation. There is but one brood in the season, as far as 

 I have been able to determine, although I have seen nests in the 

 early part of August with rather tender fledglings. The period 

 of incubation ranges from fourteen to fifteen days. 



Family CORYID.E. 



Corvus Americanus, Audubon. 



The above species is very abundant throughout the summer in 

 this section of the country', and the writer has observed through 

 the severest winter weather numberless individuals roosting in 

 the junipers and cedars of the hills of the Wissahickon, when the 

 snow stood several inches upon the ground. The birds commence 

 pairing about the last of April, seldom earlier than the fifteenth, 

 and shortly afterwards commence building. The nests are usually 

 built upon the various species of oaks, and occasionally upon 

 some of Pinus. They are large in dimensions, fully 18 inches in 

 diameter at the base, and from 8 to 10 inches in depth; the thick- 

 ness of the walls is from 3 to 4 inches. They are constructed of 

 coarse rude sticks externally, of the thickness of a lady's ring 

 finger, mostly fragments of dead branches that had fallen from 

 the oaks and chestnut. Within are smaller twigs of the same 

 covered by a few dried leaves of Quercus and Fagus to relieve its 

 hardness. All the nests that I have examined, and I have had 

 abundant opportunities, answer to the above description, whicii 

 will be found to differ materially from others. Usually but one 

 brood is reared in a season ; the writer has met with two, but 

 this is of rare occurrence. 



Nests have been taken close by the dwellings of man, showing 

 the friendly disposition of the authors. Usually the species is 

 very shy and builds in places seldom visited. When with young 

 the birds are very pugnacious, permitting no intrusion within 

 their jurisdiction. They manifest the most tender regard for their 

 progenj', and exercise the most jealous care over them. Notwith- 

 standing the mischief they commit to the farmers' crops, and their 

 frequent raids to the poultr3^ yards, the good which they accom- 



