. Birds of the United States east of the Rocky Mountains, a manual for the identification of species in hand or in the bush;. Birds; Birds. 10 EXTERNAL PARTS. but form the best and lightest of all flying organs. Some study of the parts of feathers and a knowledge of the descrip- tive terms applied to them are important. Parts and kinds of feathers. — Every feather1 consists of the main scape, or stem, and the two ivebs. The scape has first the hollow portion, the calamus or quill, and then the four-sided solid portion, the rhachis, which ex- tends to the tip of the feather. The rhachis bears o
. Birds of the United States east of the Rocky Mountains, a manual for the identification of species in hand or in the bush;. Birds; Birds. 10 EXTERNAL PARTS. but form the best and lightest of all flying organs. Some study of the parts of feathers and a knowledge of the descrip- tive terms applied to them are important. Parts and kinds of feathers. — Every feather1 consists of the main scape, or stem, and the two ivebs. The scape has first the hollow portion, the calamus or quill, and then the four-sided solid portion, the rhachis, which ex- tends to the tip of the feather. The rhachis bears on each of its sides lateral processes called barbs. These, with the rhachis, form the spreading portion of the feather, the vane. The calamus has an opening at the bottom through which the pulp penetrates, and another open- ing, the superior aperture or umbilicus, on the lower side where the calamus joins the rhachis. The barbs are narrow plates obliquely joining the rhachis, and tapering to points at their free ends, their edges being directed upward and downward when the vane is horizontal. On the sides of the barbs are minute processes, called barbules, branching from the barbs as the barbs branch from the rhachis. These barbules are often serrated and terminated by little hooks which interlock with hooks on the next barbule. (All these parts can be seen with the naked eye, or by the aid of a magnifying glass. With a microscope, the barbules will be found to divide again into barbicels or cilia and Jwoklets, forming a fringe to the barbules.) This gives firmness to the vane. If there is no inter- locking of barbules, doivny2 feathers are formed. Sometimes the scape is very long, and the barbs are very short; such feathers are called filament2 feathers, or 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 ori
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbirds, bookyear1898
