FORM AND HABIT: THE WING. 19 birds, important relation between form and habit. Many terrestrial species rely on their dull, protective covering to escape observation, taking wing only when danger is so near that it is necessary for them to get under way at once. Consequently, Quail, Partridges, and Grouse, much to the amateur sportsman's discom- fiture, spring from the ground as though thrown from a catapult, and reach their highest speed within a few yards of the starting point, while the Albatross is obliged to face the wind and run some distance over the ground or water before slowly lifting itself into the air. There, however, it can remain for hours or even days without once alighting. The Frigate Bird, or Man-o'-War Bird, has a body scarcely larger than that of a chicken, but its tail is one foot and a half in length, and its wings measure seven to Fig. 7.— Frigate Bird. (Expanse of wings, 7 to 8 feet.) eight feet in extent. Having this enormous spread of sail, its flight is more easy and graceful than that of any living bird. I have seen hundreds of these birds floating in the air, facing the wind, without apparent change of position or the movement of a pinion, for long intervals of time. From this extreme development of the wing as a flight-organ, let us turn to those birds who have not the power of flight. The Ostrich, Khea, Emu, and Cassowary are familar representatives of this group. It is generally believed that these birds have lost the power
