Passing over the Sharp-winged Grouse (Falcipennis falcipennis) of northeastern Asia, which resembles the Canada Grouse but differs in having the outer flight-feathers narrowed and sickle-shaped, we come to the well-known Pinnated Grouse, or Prairie Hens (Tympanuchus), which make their homes on the broad prairies of the Mississippi Valley and a few other isolated but topographically similar localities. They are fine large birds, some seventeen to nineteen inches long, with a brownish and dusky barred plumage, and the males are further characterized by the presence of an erectile tuft of stiff elongated feathers, and an inflatable air-sac on each side of the neck. The females lack the air-sac and have the neck-tufts rudimentary. The principal species is the Prairie Hen, or Prairie Chicken (T. americanus) , of the prairies of the middle West from Wisconsin and Indiana to Dakota and middle Kansas. They are usually resident wherever found, but occasionally there is some semblance of a migration during severe winters, and curiously it is only the females which change their range, the males being left to “brave the winter’s cold.” At the beginning of the nesting season the “love-making” of the males is an interesting spectacle. Selecting some high, dry knoll, where the grass is short, ” scratching grounds ” as they are called, they congregate in the early morning in parties of from a dozen to often fifty. The males inflate the air-sacs until they look “like two ripe oranges on each side of the neck,” at the same time throwing forward the long black neck-tufts, ruffling up the body feathers, and dropping their wings to the ground. “Then it is,” says Caton, “that the proud cock, in order to complete his triumph, will rush forward at his best speed for two or three rods through the midst of the love-sick damsels, pouring out as he goes a booming noise, almost a hoarse roar, only more subdued, which may be heard for at least two miles in the still morning air. This heavy booming sound is by no means harsh or unpleasant; on the contrary, it is soft and even harmonious. When standing in the open prairie at early dawn, listening to hundreds of different voices, pitched on different keys, coming from every direction and from various distances, the listener is rather soothed than excited. If this sound is heavier than the deep keynotes of a large organ, it is much softer, though vastly more powerful, and may be heard at a much greater distance.” The birds disperse when the sun is half an hour high, to assemble the next morning, and so on for a week or two until all have made satisfactory matches. The nesting site is usually selected with little care as regards safety from disturbance, being a slight depression under a bush or among grass and weeds. Many nests are annually destroyed by the burning over of the ground, by being plowed under, or by predatory animals. The eggs are usually from eight to fourteen, though as many as twenty-one have been noted. The period of incubation is from three to four weeks, and the young run about as soon as they are out of the shell. Their care devolves entirely upon the female. A well-marked subspecies, Attwater’s Prairie Hen (T. a. attwateri), is found along the coasts of Louisiana and eastern Texas. It is lighter in -color and has considerably more of the tarsus naked, while along the eastern border of the Great Plains is found the still smaller and lighter colored Lesser Prairie Hen (T. pallidicinctus).