. The bird, its form and function. Birds. 22 The Bird The first intimation of the appearance of a feather, or of down, is shown by a thickened group, or pimple, of ceUs in this under layer of skin, which grows and presses upward toward the outer la}'er—the epidermis. This is exactty the way in which the scales of fishes and reptiles begin to form; and if, at this stage, the tiny projection should flatten out, the shining scale of a carp, the armor. Fig. 11.—Sprouting feathers of a 12-day embryo chick. Magnified diameters. of an alligator, or the cobble-scale of an iguana lizard might resul
. The bird, its form and function. Birds. 22 The Bird The first intimation of the appearance of a feather, or of down, is shown by a thickened group, or pimple, of ceUs in this under layer of skin, which grows and presses upward toward the outer la}'er—the epidermis. This is exactty the way in which the scales of fishes and reptiles begin to form; and if, at this stage, the tiny projection should flatten out, the shining scale of a carp, the armor. Fig. 11.—Sprouting feathers of a 12-day embryo chick. Magnified diameters. of an alligator, or the cobble-scale of an iguana lizard might result. Indeed, in the feathers of a penguin we find transition stages of flat, almost unsplit feather- scales; while on the legs and feet of birds are reptile-like scales. The evolution of scales, hair, and feathers is a most interesting problem, most of the details of which are beyond the scojie of this work. Suffice it to sav that. 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 Beebe, William, 1877-1962. New York, Holt
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbirds, bookyear1906
