. 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. 124 a EN ERA L OJiXrniOLOG r. uiinimum lonptlis of taraiis are nearly thirty and iindtT tlirce per cent, of a bird's wliujo length. The Horny Integument of the Foot rpquirps particular attrntion. That jmrt of tho limb whir-h is (lovciid of feathers iw eovcred, like the bill, by a hardened, tliieUened, ditiid integument, varying in
. 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. 124 a EN ERA L OJiXrniOLOG r. uiinimum lonptlis of taraiis are nearly thirty and iindtT tlirce per cent, of a bird's wliujo length. The Horny Integument of the Foot rpquirps particular attrntion. That jmrt of tho limb whir-h is (lovciid of feathers iw eovcred, like the bill, by a hardened, tliieUened, ditiid integument, varying in texture from homy to leathery. This sheath is called tho potluthnu (Or. novt, noSos, jjoh.'*, podim, foot, mid OriKt], tlicke, sheath). It is more corneous iu land hinls, and in water birds more leathery ; this general distinction has but few exceptions. The perfectly horny envelope is tight, and iunnovahly fixed or nearly so, while the skinny styles of slicntji are looser, and may usually be sli]>}>ed about a little. Tho integument may differ on diHeniit parts of the same leg, and in fact generally does so to some extent. Uulike the sheath of the bill, the podotheca is never shnido and continuous, being divided and subdivided in various ways. The lower part of the cms, when naked, and the tarsus and toes, always have their integinnent cut up into scales, plates, tubercles, and other special formations, which have received particular names. The maimer and character of such divi-^ions are often of the utmost coiise(iuence in classification, especially among tho higher birds, since they arc (piite sigtiificant of genera, families, and even some larger iteV Fin. 3G. —Booted laminlplantar tarsus of a robin. Nat. 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 Coues, Elliott, 1842-1899. B
Size: 1285px × 1945px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectbirds, bookyear1884