. Key to North American birds. 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 and lower California, with which are incorporated General ornithology: an outline of the structure and classification of birds; and Field ornithology, a manual of collecting, preparing, and preserving birds. Birds; Birds; 1887. Fig. 48. — Semipal ination in Ereunetts iiat. Fii;. A.). — feemj- palniateil bases of toes of Symphemia; nat. size. It is actually thi. exliibit the trans
. Key to North American birds. 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 and lower California, with which are incorporated General ornithology: an outline of the structure and classification of birds; and Field ornithology, a manual of collecting, preparing, and preserving birds. Birds; Birds; 1887. Fig. 48. — Semipal ination in Ereunetts iiat. Fii;. A.). — feemj- palniateil bases of toes of Symphemia; nat. size. It is actually thi. exliibit the transition from the perching to the gradient focjt, in some reducti<m of the hind toe, which is nevertheless in most cases still on the same level as the rest (fig. 38, V). In the gallinaceous or rasorial (Lat. rasor, a scraper) birds, which are essentially terrestrial, and noted for their habit of scratching the ground for food, the hind toe is decidedly elevated and shortened in almost all of the families (fig. 35). Such reduction and uplifting of tlu^ is carried to an extreme in inost of tlie waders, or g7'al- latores, in many of which tliis toe disapiiears (figs. 38, a, 39). It is scarcely practicable to recognize special modifications of such gradient or grallatorial feet, since they merge insensibly into one anotlier. The herons, which are the most arboricole of the waders, exhibit a reversion to the iusessorial type, in the length in- cumbency of the hallux. TIk; ujode of uinon of the front toes of the walkers and waders is somewhat char- acteristic. The toes are either cleft quite to the base, or there joined by small webs ; probably never actually coherent. Such basal webbing of the toes is called semipalmation ("half-webbing"), same thing that occurs in many birds of prey, in most gallinaceous birds, etc. ; the term is mcjstly restricted, in descriptive ornithology, to tliose loading birds, or grallatores, in which it occurs. Sucli basal webs
Size: 1406px × 1777px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectbirds, bookyear1887
