OF EASTERN PENNSYLVANIA. 47 



by the first brood, the soiled materials are thrown 

 out, and a fresh supply introduced. Sitting com- 

 mences about the 25th of May, and lasts until the 

 5th of June; thus making the period of incubation 

 between 1 1 and 1 2 days. 



The young when hatched are alternately fed by 

 each parent. Their food consists of earthworms, 

 diptera, coleopterous and lepidopterous larvae, 

 with berries occasionally when in season. As 

 they increase in size and strength, their bill of fare 

 is augmented. Beetles and moths of the smaller 

 kinds are in great demand. 



When the young birds are nearly able to shift 

 for themselves, they are entrusted to the care of 

 the male, while the female busies herself in pre 

 paring for a second brood. Thus it happens that 

 the male is charged with double duty. Upon him 

 devolve the maintenance of his mate and the 

 care of the older children. On their arrival, the 

 Blue Birds subsist principally upon insect-food, 

 yet the few remaining berries of the cedar and 

 common-juniper which may be clinging to their 

 branchlets, together with the seeds of Chenopo- 

 dium album, Amarantus a^is, A. hybridus, and 

 others, are keenly relished. In the stomachs of 

 several individuals we have discovered traces of 

 Pangus caliginosus, Harpahis pensylvanicus, Pla- 

 tynus cupripennis, Cr atony chus cinereiis among 

 beetles; CEdipoda sulphurea, CE. neb^dosa among 

 orthoptera, besides ants and earthworms. As the 

 season advances, Musca domestica, Tabamis lineola, 



