Beginners' zoology . y possess few or no barbicels;sometimes they lack the rachis (Fig. 293). The pin feath-ers are dehcate horny shafts, greatly resembling hairs, butthey may have a tuft of barbs at the ends. A feather grows from a small projection (or papilla) foundat the bottom of a depression of the skin. The quill isformed by being moulded around the papilla. Do you seeany opening at the tip of the quili for blood vessels to enterand nourish the feather .- What is in the quill ? (Fig. 291.)The rachis ? A young con-tour or quill feather is in-closed in a delicate sheathwhich is cast off wh
Beginners' zoology . y possess few or no barbicels;sometimes they lack the rachis (Fig. 293). The pin feath-ers are dehcate horny shafts, greatly resembling hairs, butthey may have a tuft of barbs at the ends. A feather grows from a small projection (or papilla) foundat the bottom of a depression of the skin. The quill isformed by being moulded around the papilla. Do you seeany opening at the tip of the quili for blood vessels to enterand nourish the feather .- What is in the quill ? (Fig. 291.)The rachis ? A young con-tour or quill feather is in-closed in a delicate sheathwhich is cast off when thefeather has been you seen the sheathincasing a young feather ina moulting bird? There are considerableareas or tracts on a birdsskin without contour feath-ers. Such bare tracts arefound along the ridge of the breast and on the sides ofthe neck. However, the contour feathers lie so as to over-lap and cover the whole body perfectly (Fig. 294). The shedding of the feathers is called moulting. Feathers,.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectzoology, bookyear1921
