File:The bird, its form and function (1906) (14569099998).jpg

Identifier: birditsformfuncti00beeb (find matches)
Title: The bird, its form and function
Year: 1906 (1900s)
Authors: Beebe, William, 1877-1962
Subjects: Birds -- Anatomy Birds -- Physiology
Publisher: New York, H. Holt and company
Contributing Library: American Museum of Natural History Library
Digitizing Sponsor: Biodiversity Heritage Library

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^ inrelative position or a general vague likeness of function.We are accustomed to speak of the mouth of a starfish,the arms of a sea-anemone, the foot of a snail: in theserespective cases, structures specialized for receiving food, Beaks and Bills 225 reaching about, or for ))rogression being understood. Butno one would think of alluding to a birds lips or nose; bothare included in the terms beak, or bill, and nostrils. The finding and securing of food being the most im-portant problem which birds have to solve for themselves,it is for these purposes, and especially the last mentioned,that we find bills most adapted. This is so universalh
Text Appearing After Image:
Fir.. l(v). —Rill nt American Raven. the case that we may often judge accurately of the kindof food of a certain bird from a glance at its beak. As is the case with so many other avian structures,the horn), toothless beak or bill is duplicated elsewherein Nature only in a group of reptiles, the turtles and tor-toises, whose mandibles furnish a splendid example ofparallel evolution. In certain of those long-extinct Dinosaurs, such as 226 The Bird Triceratops, an interesting transitional condition is found.The front of the mouth was beak-Hke and horny, whilefarther back were the masticators teeth. Starting with the generalized beak of the Archce-opteryx, which, we remember, was furnished with teeth,we are almost at a loss in which direction to turn,so man)^ and so varied are the beaks of modern birds.No trace of teeth, however, is to be found in the adultsof any of them. The bill of a crow or raven and, to alesser extent, that of his near relatives, the jay and theblackbird, is perhap

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