. Animal locomotion or walking, swimming, and flying : with a dissertation on aëronautics. and heron(fig. GO, p. 126) ; and others whose bodies are comparativelyheavy, while their wings are insignificantly small—as thesphinx moth and Goliath beetle (fig. 58) among insects, andthe grebe, quail, and partridge (fig. 59, p. 126) among apparent inconsistencies in the dimensions of the bodyand wings are readily explained by the greater musculardevelop-ment of the heavy-bodied short-winged insects and birds, andthe increased power and rapidity with which the wings in themare made to oscilla
. Animal locomotion or walking, swimming, and flying : with a dissertation on aëronautics. and heron(fig. GO, p. 126) ; and others whose bodies are comparativelyheavy, while their wings are insignificantly small—as thesphinx moth and Goliath beetle (fig. 58) among insects, andthe grebe, quail, and partridge (fig. 59, p. 126) among apparent inconsistencies in the dimensions of the bodyand wings are readily explained by the greater musculardevelop-ment of the heavy-bodied short-winged insects and birds, andthe increased power and rapidity with which the wings in themare made to oscillate. In large-winged animals the movements PROGRESSION IX OR THROUGH THE AIR. 125 are slow; in small-winged ones comparatively very rapid. Thisshows that flight may be attained by a heavy, powerfulanimal with comparatively small wings, as well as by alighter one with enormously enlarged wings. While there isapparently no fixed relation between the area of the wingsand the animal to be raised, there is, unless in the case ofsailing birds,1 an unvarying relation between the weight of J-. Fig. 5S.—Under-surface of large beetle (Goliathus mica a*), with deeply con-eave and comparatively small wings (compare with butterfly, fig. 57), showsthat the nervures r, d^ e, f, n, n, ri of the wings of the beetle are arrangedalong the anterior margins and throughout the substance of the wingsgenerally, very much as the bones of the arm, forearm, and hand, are in thewings of the bat, to which they bear a very marked resemblance, both intheir shape and mode of action. The wings are folded upon themselves atthe point e during repose. Compare letters of this figure with similar lettersof fig. 17, p. 36.—Original. the animal, the area of its wings, and the number of oscilla-tions made by them in a given time. The problem of flightthus resolves itself into one of weight, power, velocity, andsmall surfaces; versus buoyancy, debility, diminished speed, 1 In birds which skim, sail, or glide, the
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