296 FEET OF LONG-WINGED BIRDS. 



than the feet for the aquatic part of their food, and 

 as many of them alight on the water chiefly, or exclu- 

 sively, for the purposes of rest, and not of feeding, 

 they have less of positive character in their feet than 

 the swimming or the diving iDirds, and less even than 

 those birds which, like the gannet, use the feet in 

 working upward to take the wrng. These feet are 

 accordingly less stout in the tarsi, and less produced 

 in the toes and webs, and they are without the oblique 

 motions, and have the toes and webs turned nearly in 

 the direction of the front : the outer and inner of nearly 

 the same length, and the middle one little different. 

 The webs, too, are much narrower in proportion to 

 the length of the toes than in the swimming birds, 

 and the hind toe always very short, sometimes a 

 mere tubercle, or a rudimental nail, but differently 

 placed according to the habit. 



These birds can all swim, and most of them ride 

 very buoyant on the water, and they sometimes feed 

 as well as rest there ; but as their neck is short, and 

 they do not dive, they command a very limited range 

 of the water when they are on its surface. One prin- 

 cipal use of their feet is in alighting and rising from 

 the water, which they do more readily than any other 

 birds. They come down with a twitch, half on the 

 surface, and are on the ^nng again almost in an 

 instant. In alighting, they advance the feet flat under 

 the body, with the anterior edge of the webs in 

 advance of the centre of gravity ; and as the princi- 

 pal joints act parallel to the mesial plane, the least 

 exertion in pushing down the webbed feet, reacting 

 on the centre of gravity, and raising it a little back- 

 ward as well as upward, throws the bird so clear of 

 the water, that its open wings take the air and it is 

 instantly in the sky. All this is accomplished with- 



