GALLINACEOUS BIRDS 4I 
America, as well as a number of others, to belong to 
the pheasant family (Phasianide) which in that view 
includes the turkeys, the pheasants, the partridges, the 
grouse and some others. Until recently American natu- 
ralists were disposed to regard the pheasant family as 
limited to the true pheasants, the turkeys, domestic fowl 
and guinea fowl; and to place the grouse and the par- 
tridges and quail in a family by themselves (Tetraont- 
de), the grouse family. For the partridges of the Old 
World the sub-family Perdicine was established, and 
another sub-family (Odontophorine) for the quails 
of the New World. By American ornithologists these 
two groups have recently been given family instead of 
sub-family rank, and are called Perdicide and Odon- 
tophoride. The turkeys have also been given family 
rank, and are now called Meleagride. 
Although the various birds belonging to this group 
may differ widely in many respects, all have certain 
characteristics in common. In all the body is heavy 
and round, owing to the great development of the pec- 
toral muscles—what we call the breast in a bird—the 
head is small and the neck rather long. The bill is short 
and stout, much arched, and overhangs the lower 
mandible. 
The digestive system has certain peculiarities corre- 
lated with their habits of life. There is a large crop 
capable of great distention; a strong gizzard—except in 
the sage grouse—lined with a tough, almost horny, 
coating, peculiarly adapted to grinding the hard sub- 
