. The bird, its form and function. Birds. I 90 The Bird breast muscle, which makes possible the all-important downward sweep of the wings, weighs one-fifth as much as the entire bird, bones and all. This arrangement of a great weight of muscle hung below the point of attach-. FiG. 139.—Wing and breast of Pigeon, showing immense pectoral muscles, and tendons of wing used in flight. ment of the Avings is, for mechanical reasons, the only one possible in a l)ird of flight; since anj' excess of weight above the wings would instantly overbalance the bird. If we remove the skin from the upper arm of
. The bird, its form and function. Birds. I 90 The Bird breast muscle, which makes possible the all-important downward sweep of the wings, weighs one-fifth as much as the entire bird, bones and all. This arrangement of a great weight of muscle hung below the point of attach-. FiG. 139.—Wing and breast of Pigeon, showing immense pectoral muscles, and tendons of wing used in flight. ment of the Avings is, for mechanical reasons, the only one possible in a l)ird of flight; since anj' excess of weight above the wings would instantly overbalance the bird. If we remove the skin from the upper arm of a bird,. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Beebe, William, 1877-1962. New York, Holt
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbirds, bookyear1906
