FORM AND HABIT: TUE WING. 19 



birds, important relation between form and ba])it. 

 Many terrestrial species rely on their dull, protective 

 covering to escape observation, taking wing only when 

 dani^er 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- 

 iiture, 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 hfting itself into the air. There, 

 however, it can remain for hours or even days without 

 once alio:htinor. 



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 Avings 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 wdio have not 

 the power of flight. The Ostrich, Rhea, Emu, and 

 Cassowary are familar representatives of this group. It 

 is generally believed that these birds have lost the power 



