BIRDS 175 
along its edges with a kind of fringe. Both the fringe of 
the tongue and the. tooth-like processes of the mandibles 
serve the purpose of strainers and help the bird to secure 
its food. The neck is long and flexible and can be thrust 
out in all directions in search of food. 
The Feathers which clothe the body are dense and 
glossy, and smeared with an oily substance which renders 
them waterproof. A layer of soft warm down covers the 
skin. The tail is short. 
Mode of Swimming.—Note the shape and position 
of the legs. They are placed in such a way as to bring 
the propelling power into a position where it will be most 
effective in forcing the animal through the water. 
In swimming the stroke is made by first drawing the 
foot forward, when the toes close and the webs are folded 
together so that the minimum amount of resistance is 
offered to the water. The back stroke is made by spread- 
ing the toes out and hence unfolding the webs, placing 
the legs in an oblique position and forcing them. back- 
ward so as to strike the water with the broad expanded 
surface of the foot. 
Food.—The Duck lives on soft vegetable substances, as 
well as on worms, insects, and other small animals. 
These are taken into the mouth with the mud and ooze, 
which are got rid of through the processes along the edges 
of the bill, and the fringes of the tongue. 
Uses.—The Duck is highly prized not only on account of 
its flesh, but also for its eggs. Considerable trouble is 
sometimes experienced in training Ducks to lay in specially 
prepared nests ; the birds generally prefer to lay in some 
secluded spot of their own choosing, or even on the bare 
ground away from the nests provided. 
