108 THE FEET 
In short-tailed birds like Murres, the feet, when extended backward, 
act as rudders in flight. It may be added that all the Water-birds, the 
Galline, Columbe and Raptores, carry the feet extended backward in 
flight, while all the Passeres, or Perching Birds, carry them drawn up 
forward. In the intermediate groups (Cuckoos, Trogons, Wood- 
peckers, Swifts, Hummingbirds and Parrots) the manner in which the 
Fia. 19. Toes of Ruffed Grouse. Naked in summer, fringed in winter to serve as 
snowshoes. Illustrating seasonal adaptation in structure. 
feet are held in flight does not appear to be definitely known, though 
it seems probable that they are drawn up as in the Passeres. (See Town- 
send, ‘‘A Labrador Spring,” pp. 180-205.) 
The longer-winged diving birds, like Cormorants and Water-Tur- 
keys, use only the feet to propel them when under water; Grebes and 
Loons also use the feet for a similar purpose, and to a lesser extent 
the wings. 
The relation between the two organs of locomotion, wings and feet, 
should be observed, when it will be found 
that when the former are greatly developed the 
feet are correspondingly small (e. g. Man-o’- 
war-bird; Swallows), while when the feet are 
large the wings are proportionately short and 
weak (e. g. the Rails and Gallinules). 
In securing food, feet are of service in 
scratching (e.g. Galline; Fox Sparrows), while in 
predaceous birds long, recurved talons and grasp- 
ing power reach their maximum among birds. 
Parrots use the foot as a hand, and many 
birds employ it to gather and place nesting 
material. With gallinaceous birds, particularly 
; those that have spurs, the foot is a weapon. In 
Fra. 20. Foot of Osprey; Herons and Goatsuckers, the middle-toe has a 
a ane Sppeesd lateral terminal comb or pectination the func- 
surface of aaa tion of which is unknown. 
