Natural history of animals; . Crown. Fore neck. , or leg. Tarsus, or in-step. Interior Fig. 102.— Showing the names of some of the principal parts of a Bird. BIRDS. 73 air; even their bones are hollow, hence very light inproportion to their size. The general form of a Bird,and the names of some of the principal external parts,are shown in Figure 102. The skeleton and the namesof its principal parts are shown in Figure 103. It isan interesting fact that the form and the skeleton of abird su
Natural history of animals; . Crown. Fore neck. , or leg. Tarsus, or in-step. Interior Fig. 102.— Showing the names of some of the principal parts of a Bird. BIRDS. 73 air; even their bones are hollow, hence very light inproportion to their size. The general form of a Bird,and the names of some of the principal external parts,are shown in Figure 102. The skeleton and the namesof its principal parts are shown in Figure 103. It isan interesting fact that the form and the skeleton of abird suggested the right way in which to build a shipin order to combine strength with swiftness. Although the body of Birds is covered with feathers,these do not grow from the whole surface, but are ar-ranged in rows and patches, with bare spaces are made up of a hard central portion, or shaft, h. Fig. 103. — Skeleton of a Bird. k, head; nv, neck vertebrae; c, wrist; tk, thumb; mc^ metacarpus, or hand; />/t,phalanges, or fingers; r, radius; w, ulna; /*, humerus; sc, scapula, or shoulder-blade; s, phalanges, or toes. 74 VERTEBRATES : BIRDS. and vane on each side, the latter being the broad portionwhich consists of delicate plates that are united by-minute barbs along their edges, and thus made firm,—the plates not separating from one another when pressedagainst the air, as in flying. There are, however, downyfeathers on every Bird, or such as do not have the platesunited. The plumage of Birds is made waterproof bythe oil with which they dress their feathers, and whichis obtained from a gland situated on the tail. Theyshed their feathers twice a year, and in many kinds thewinter pluma
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
