. Key to North American birds. Containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary, inclusive of Greenland and Lower California, with which are incorporated General ornithology: an outline of the structure and classification of birds; and Field ornithology, a manual of collecting, preparing, and preserving birds. Birds; Birds. structed, by loss of some of the digits that five-fingered animals^ possess, and by the compres- sion of those that are left. The wing proper begins at the shoulder-jo
. Key to North American birds. Containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary, inclusive of Greenland and Lower California, with which are incorporated General ornithology: an outline of the structure and classification of birds; and Field ornithology, a manual of collecting, preparing, and preserving birds. Birds; Birds. structed, by loss of some of the digits that five-fingered animals^ possess, and by the compres- sion of those that are left. The wing proper begins at the shoulder-joint, where it hingea freely upon the shoulder, in a shallow socket formed conjointly by the shoulder-blade or sca/pula, and by the coracoid bone; these two, with the clavicles, eoUar-bones or mer- ry-thought, fwreulum, form- ing the shoulder-girdle, or pectoral arch (figs. 56, 59). The wing ordinarily con- sists,' in adult life, of ten or eleven actually separate bones; in the embryo (see fig. 39) there are indications of several more at the wrist-joint, which speedily lose their individual identity by fusing together and with bones of the hand. Aside from these, there is often an accessory ossicle at Fro. 28.—Mechaniam of elbow-joint. (See explanation of lig. 27.) the shoulder-joint (fig. 56, ohs), sometimes one at the wrist-joint, occasionally an extra bone at the end of the principal finger. The normal or usual number is shown in fig. 37, taken from a duck {Clamgula isla/ndica), in which there are eleven. The upper arm-bone, h, reaching from the shoulder A to the elbow B, is the humerus. In the closed wing, the humerus lies nearly in the position of the same bone in man when the elbow is against the side of the body; in extension of the wing, the elbow is borne away from the body, as when we raise the ai-m, but carry it neither forward nor backward. A peculiarity of the bird's humerus is, that it is rotated on its axis through about the quadrant of a circle, so that what i
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbirds, bookyear1894
