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 The thigh hardly projects beyond the skin of the trunk, as may be noticed in a plucked fowl. The thigh extends forward from the hip joint (Figs. 286, 299) in order to bring the point of support forward under the center of weight. Why are long front toes more necessary than long hind toes? As the bird must often bring its head to the ground, the hip joints are near the dorsal surface and the body swings between the two points of support somewhat like a silver ice pitcher on its two pivots. Hence stooping, which makes a man so unsteady, does not cause a bird to lose steadiness.

The wing has three divisions which correspond to the upper arm, forearm, and hand of man (Fig. 286). When the wing is folded, the three divisions lie close alongside each other. Fold your arm in the same manner. The similarity of the bones of the first and second divisions to the bones of our upper arm and forearm is very obvious (Fig. 286). Explain. The hand of a bird is furnished with only three digits (Fig. 287). The three palm bones (metacarpals) are firmly united (Fig. 287). This gives firmness to the stroke in flying.

(after Parker).

DG. 1-3, digits; MC. 1-3, metacarpals; CC. 3, wrist.

(c), (after Parker).

That the bird is descended from animals which had the fingers and palm bones less firmly united is shown by comparing the hands of a chick and of an adult fowl (Figs. 287, 288). The wrist also solidifies with age, the