USE OF THE KEYS. 33

the most highly developed ones, Thrushes, Bluebirds, etc. Two main divisions are given: first, Water Birds; second, Land Birds. In no

(Bluebird, slightly reduced).

FIG. 2.—Topography of a bird.

case will it be difficult to decide in which of these groups a bird be-

longs. Now glance over the illustrations and select the one which

you think most» nearly resembles the bird you are identifying. At 4 l