পাতা:পদার্থবিদ্যাসার.djvu/১১১

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  • 3rd: The goose kind; the bill of these is smooth, ‘broad at the end, and covered with a thin membrane; as geese, ducks, swans, &c. .

4th. The crane kind, whose bill is nearly cylindrical, as herons, wood-cocks, bustards. 5th. The pou li ry kind : the bill in these is convex, the superior mandible is voluted over the inferior; as the เหstrich, peacock, turkey, &c. 6th. The sparrow kind, which have conical, sharp. pointed bilis; such are pigeons, larks, nightingales, &c. Pup. ls any ihing partieular te be observed of.tive production and structure of a bird 2 wt. Yes. Ohserve how ii acquires its existemice, out of that matter or substance with which an egg is filled: and this is effected only by a brooding heat. The structure of birds is also curious, and a proof of great skill and wisdom. How well adapted is their forus for flying ! The substance of their bones is much thinบer than that of land animals, that they may be lighter and better able to mount in the air. And that the thinness of the bones should not render them weaker, the substance of them is stronger and harder. ... With their pointed beak they can more easily cut the but what is most observable in birds is their being capable of flying in the 'air, and sotne of them with ຂໍາing rapidity i. purpose, their wings are constructed. But the flight of birds