. Key to North American birds [microform] : containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary, inclusive of Greenland. Birds; Ornithology; Oiseaux; Ornithologie. 212 GENERAL gullet of mauy small birds, as various genera ot Frinffillido', and Corvida, is much more disten- sible than is commonly supposed, and may bo found crammed with seeds which there find rest- ing-place for some time. The lish-eating birds, as herons, cormorants, loons, and others, liavo also capacious gulle
. Key to North American birds [microform] : containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary, inclusive of Greenland. Birds; Ornithology; Oiseaux; Ornithologie. 212 GENERAL gullet of mauy small birds, as various genera ot Frinffillido', and Corvida, is much more disten- sible than is commonly supposed, and may bo found crammed with seeds which there find rest- ing-place for some time. The lish-eating birds, as herons, cormorants, loons, and others, liavo also capacious gullets. The Australian bustard, Eupodotis australis, has an oesophagus capa- ble of such extraordinary distension that it hangs down in front of the breast when intlatcd with air, as it is in the amatory display in which that species is wont to indulge. Aside from mere distensibility of transient character, the oesophagus of uuuiy birds becomes modified anatomically into a special pouch,—the crop or craw, ingluvies, where the food is detained to be macerated in a special secretion before ])assiug on to the true stomach. Such definite crops occur iu birds of prey, whi(!h gorge such masses of food in their irregular voracious banquets that it cannot all bo received into the stomach at once; and likewise throughout the orders of Columbine and Gallinaceous birds, which habitually feed upon seeds and other fruits so hard that tliey are advantageously macerated as a preliminary to true digestion. The common fowl funiislics a gootl illustration of a large, definite, single and median crop ; in pigeons it is a jiair of lateral dilatations (set; frontisp.). In these latter birds, when they are rearing their young, the secretion of the ingluvies, always copious, becomes still more so, and of a milky character in consequence of the activity of the altered mucous surface; it is regurgitated into the mouths of the young, along with the macerated grains. " This phmiomenon is the nearest a
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbirds, bookyear1884
