FORM AND HABIT: THE WING. 19 



birds, important relation between form and babit. 

 Many terrestrial species rely on tlieir dull, protective 

 covering to escape observation, taking wing only wlien 

 danger is so near tbat it is necessary for tbem to get 

 under way at once. Conseipiently, Quail, Partridges, 

 and Grouse, mueli to tlie amateur sportsman's discom- 

 fiture, spring from tlie ground as tliougli thrown from 

 a catapult, and reach their highest speed within a few 

 yards of the starting point, while the All)atross is obliged 

 to face the wind and run some distance over the ground 

 or water before slowly lifting itself into tlie air. There, 

 however, it can remain for hours or even days without 

 once alighting-. 



The Frigate Eird, or Man-o'-War Bird, has a body 

 scarcely larger than that of a chiclcen, l)ut its tail is one 

 foot and a half in length, and its wings measure seven to 



Frio'att; Bird. (Expanse of wings, 7 tr. ^ 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 tlie wind, -without apparent change of 

 position or the movement of a piinon, 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, Kliea, Emu, and 

 Cassowary are familar representatives of this group. It 

 is generally believed that these birds have lost the power 



