The true Partridges ( Perdix) of the Old World are known from the preceding genera by possessing sixteen or eighteen feathers in the tail, feet without spurs, and a similar or nearly similar plumage for both sexes. The Common Partridge (P. perdix) of Europe and central Asia is about twelve inches long, the plumage being gray and reddish brown, the male, and exceptionally the female, with a horseshoe-shaped patch of chestnut on the lower breast. This is a favorite bird among all lovers of birds and seems to be aided rather than limited by extending civilization. It avoids woodlands and frequents especially open, cultivated grounds or heaths and commons, going about, except during the nesting season, in coveys of from half a dozen to twenty or more, and is a favorite game bird throughout its range. Rarely if ever perching in trees, it spends its whole time on the ground, though when pushed rises with a loud whirring sound and enjoys a strong, straight flight. The nest is usually well concealed under a tuft of long grass or a bush, and contains from ten to fifteen, or even as many as twenty, pale olive-brown eggs. This species. appears to break up into a number of geographic races, of which the so-called Migratory Partridge (P. p. damascena) of the Alpine regions of western Europe is an example. This form is much smaller than the species and has the bill and feet yellowish instead of horn-gray; it comes down to the plains of southern and central Europe in winter.