. The bird; its form and function . )oint backward toward the gullet and mustbe of great help to the bird in guiding and swallowing itsfood. These teeth are especially abundant around theglottis, or opening to the windpipe, guarding it fromchafing or from the chance of food choking it up. In ducks and geese we find tongues large and of com-plicated appearance. The edges are often toothed or Organs of Nutrition 121 fringed to correspond with the serrated or otherwiseindented edges of the mandibles. One which is before meas I write is very elaborate. It is that of a wild MallardDuck. At the tip
. The bird; its form and function . )oint backward toward the gullet and mustbe of great help to the bird in guiding and swallowing itsfood. These teeth are especially abundant around theglottis, or opening to the windpipe, guarding it fromchafing or from the chance of food choking it up. In ducks and geese we find tongues large and of com-plicated appearance. The edges are often toothed or Organs of Nutrition 121 fringed to correspond with the serrated or otherwiseindented edges of the mandibles. One which is before meas I write is very elaborate. It is that of a wild MallardDuck. At the tip is a thin, distinct flap or lamella, hornyand with smooth edges. Behind it the tongue enlargesabruptly into a thick oblong mass, deeply grooved down. Fig. of Jirown Pelican showing extreme reduction of tongue in a birdwhich swallows whole fish. the center. The edges of the anterior half are fringedwith a double line of horny hairs, while in the posteriorportion the upper hne is replaced with tooth-like struc-tures. The upper surface is smooth in front, but fartherback two central folds arise and curve over laterally,forming tube-like grooves. Still more posteriorly, fleshyrecurved teeth are visible, singly, in groups, or in regularlines. The tongue of our con:mou barnyard duck is I 22 The Dird similar to this and is well examining. The use ofsuch a complicated organ in a bird of so sin:ple feedinghabits as the duck is hard to explain. We will hardly find two tongues that are alike, andeven the tips differ, and show as wide a range of varia-
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbirds, bookyear1906
