2J4 LIFE-HISTORIES OF BIRDS 



men with a decidedly convex outline and are thence carried 

 hack to the commissural point, is so constant a character, as 

 to afford a tolerably good clue to the identification of these 

 birds. The head is notably small ; neck but moderately 

 lengthened ; and body full, especially in the pectoral region. 

 The wings are powerful, elongate, and pointed ; tail varying 

 from quadrate to graduate, but never bifurcate ; the rectrices 

 generally 12, frequently 14, but rarely 16. The gi//ard is 

 large and muscular in graminivorous species. The gullet 

 dilates into a capacious, though circumscribed crop, which 

 secretes a peculiar lacteous fluid which is intermingled with 

 macerated food and regurgitated directly into the mouth of 

 the young. 



The entire number of existing species is about three hun- 

 dred, eighty of which are included in America. They are 

 divided into the three groups : Trcroniua:* of the Old 

 World ; Gourince, of both hemispheres ; and the Cohim- 

 bincc, to which the domestic pigeon ( Colnmba //via} belongs. 

 The North American genera, excepting Columba and Ec- 

 topistcs, Dr. Cones thinks belong to the Gourince, but 

 owing to its lack of precise limitation when contrasted with 

 the Cohtmbince. he chooses not to discriminate subfamilies. 

 In Eastern Pennsylvania, we have but two species, which 

 are included in as many genera. 



Ectopistes migratorius, S 



The well-known Passenger Pigeon is plentifully found 

 throughout the North American continent. It ranges from 

 the Atlantic to the great Central Plains, and from the Gulf 

 States, thence northward to the 62 of north latitude. Its 

 arrival in the fur countries dates from the latter part of 

 May, according to Richardson. In the warm central regions 

 of British America, it reaches the 62 degree ; but in the 

 vicinity of Hudson's Bay, it is only found in very mild sum- 

 mers, as high as the 58th parallel. It is notably absent on 

 the Pacific coast. But a single individual has been captured 



