. The structure and life of birds. Birds; Evolution. i62 THE STRUCTURE AND LIFE OF 15IRUS chap. In all birds the upper beak moves slightly, in parrots freely. It is always growing, but constant friction against hard substances and of the upper against the lower beak prevents this from being apparent. The duck's beak acts as a strainer: the whale, in the so- called whalebone, has a similar instrument which lets the water pass away while retaining the food. The. Fig. 42. (i). Beak of Falcon sliowing toothed edge ; (2), of Duck showing strainer. beaks of Humming-birds are bent or otherwise shaped
. The structure and life of birds. Birds; Evolution. i62 THE STRUCTURE AND LIFE OF 15IRUS chap. In all birds the upper beak moves slightly, in parrots freely. It is always growing, but constant friction against hard substances and of the upper against the lower beak prevents this from being apparent. The duck's beak acts as a strainer: the whale, in the so- called whalebone, has a similar instrument which lets the water pass away while retaining the food. The. Fig. 42. (i). Beak of Falcon sliowing toothed edge ; (2), of Duck showing strainer. beaks of Humming-birds are bent or otherwise shaped so as to suit the forms of particular flowers down the corollas of which they dive for the honey. Falcons and other birds of prey have their upper beaks cut into teeth, an assistance in tearing their food. And In con- nection with this, it must be remembered that flesh- eating birds have nothing worthy of the name of a gizzard. Hence some tearing of the food is 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 Headley, F. W. (Frederick Webb), 1856-1919. London, New York, Macmillan
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbirds, bookyear1895
