Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: a horny exterior, and terminated in a point, from each side of which, above the cylinder, proceeds diagonally a vane, composed of proximate parallel laminae ; and here common observation, with regard to a quill, terminates. To investigate its less obvious, but more curious incidents, we must make use of the microscope. By the aid of this instrument it appears, that these laminae are not flat, as they appear to the unassisted eye, but are semitubular, having, on their outward edge, a series of bristles, set in pairs opposite one another, which clasp with the bristles of the approximate laminae, and cause that adhesiveness observable between the several laminae of the vane, and that readiness to reunite after they have been forcibly separated. The bristles are not of the same form on each side of one lamina, the lower tier forming a simple and slight curve, while the upper terminate with three or four little hooks, which serve to catch the simple corresponding bristle of the next lamina. This is the general plan by which the quill-feather of a bird, when opposed by its flat under-surface to the air, is made impervious to that subtle element, so as to support the sailing body on it alone. This general plan, however, is varied in its application to the several species. Thus, in the small and light species, the laminae and the bristles are proportionably larger, compared with the feather, than they are in larger and heavier birds. It is, as we have observed, only one edge of the semitubular lamina-, which is furnished with bristles; the opposite edge goes off in a little ledge, composed of longitudinal fibres, which little ledge is the only part of the feather found not to be of a cellular texture. The prevalente of this texture, even to the minutest parts of the: feather, ... --This text refers to an alternate Paperback edition.