250 POULTRY AND WILD BIRDS 
(6) The bird supports itself in the air by pressing down upon it with 
the wings as it flies. The principle can be demonstrated by holding an 
open umbrella in the hand while jumping from a chair. We feel buoyed 
up because the umbrella presses down upon the air, which is the same as 
saying that the air presses up against the umbrella. 
(c) To explain why the hen cannot fly so well as the robin, for example, 
notice the length of the wings of the two birds as compared with the size 
of the body. In developing the hen from her wild ancestors her wings 
have lost efficiency because she does not need to fly much; on the other 
hand, her body has become heavier. 
LESSON 5 
To learn how the form of the bird’s beak is related to the nature of its 
food: 
(a) The Hen. Notice her stout, sharp, bony beak, and how well it is 
adapted to picking up seeds and insects. 
(b) The Duck. Observe how her broad beak is adapted to finding 
insects and other food under water. 
(c) The Canary. To compare these types with still another form of 
beak we leave the poultry yard and study a canary. It would be well 
if a bird in its cage could be brought to the schoolroom for the purpose. 
Notice how short and stout its conical beak is. Then see how it prepares 
its seeds for eating, — how it crushes and shells them. 
(d) It would be instructive to compare with the above the beak of a 
typical insect eater, as a Wren, a Wood Warbler, or a Swallow. A pic- 
ture may serve the purpose. See how difficult it would be for these-birds 
to eat seed like a Canary. 
LESSON 6 
To learn how a bird’s feet are adapted to its particular needs. 
(a) The foot of the hen. Note the number of toes, their length, the 
strong claws; the horny scales covering the foot and affording thorough 
protection. All these features adapt the foot for its chief business, that 
of scratching the earth to find the seeds and insects which may lie hidden 
there. 
(b) Observe the foot of the duck. How many of its toes are united 
byaweb? Itis easy to see that this web makes a good paddle of the foot. 
(c) Now see what a good runner the hen is and how awkwardly the 
