90 
NATURAL HISTORV OF 
Among the true Gallinaceous birds, <ve find the 
different members living very much upon the ground, 
the power of flight limited, from the great weight 
of their bodies or unwieldiness of plumage, and very 
commonly an extraordinary development of the parts 
composing the tail. In the present family, the 
ground is still their prevailing habitation, though 
many of them frequently perch and roost on trees. 
Their power of flight is ample, very strong, in some, 
as the genus Pterocles, extremely rapid, but in a 
few forms almost as little used as among tbe Pa- 
vonid®. Some portion of these useful birds are 
spread over every region of the world, and in almost 
all localities. The section of the grouse to which 
the muir-fowl of Britain and the ptarmigan belong, 
occupy the wild heathy districts of the temperate 
circle, and extend to the mostbarrenand alpinemoun- 
tains, or the extremes of polar cold. The true 
gi'ouse, again, to which the European wood grouse 
belongs, occupy the forest and bushy grounds, and ex- 
tend almost as far. The partridges prefer open coun- 
tries free from wood, and draw near to cultivation ; 
but within the tropics there are one or two forms, 
which, like the grouse, prefer the brush and wood, 
where, on the branches, they are safer from the at- 
tacks of the numerous tribes of reptiles which swarm 
around them. The gangas, again, or, as they have 
been named, the sand gi'ouse, frequent the most bar- 
ren districts in the world, the plains of India and the 
trackless deserts of Africa and Arabia, far from the 
