i6o 



ANIMAL BIOLOGY 



Flying. When studying the quill feathers of the wing, 

 you saw that the wider side of the vane is beneath the 

 feather next behind it. During the downward stroke of 

 the wing this side of the vane is pressed by the air against 



FIG. 300. 



a, clambering foot of chimney sweep: t, climbing foot of woodpecker; c, perching foot ol 

 thrush; d t seizing foot of hawk; e, scratching foot of pheasant; f, stalking foot of king- 

 fisher; g, running foot of ostrich; h, wading foot of heron; /, paddling foot of gull; 

 k, swimming foot of duck; /, steering foot of cormorant; /, diving foot of grebe; , skim- 

 ming foot of coot. Question: Does any bird use its foot as a hand? (Fig. 320.) 



the feather above it and the air cannot pass through the 

 wing. As the wing is raised the vanes separate and 

 the air passes through. The convex upper surface of 

 the wing also prevents the wing from catching air as 

 it is raised. Spread a wing and blow strongly against 



