. Reptiles and birds : a popular account of their various orders, with a description of the habits and economy of the most interesting . Fig. 46.—Wing of Penguin. necessary changes in the centre of gravity, while the solidity ofthe dorsal spine gives advantage to the action of the head is terminated by a pointed bill, which aids in cleavingthe air; the feet, when short, are drawn up and concealed underthe feathers ; when long, they are stretched out beneath or behindthe tail, which is more or less expanded, and helps to support. Fig. 47.—Wing of Kamichi or Crested Screamer, the bod
. Reptiles and birds : a popular account of their various orders, with a description of the habits and economy of the most interesting . Fig. 46.—Wing of Penguin. necessary changes in the centre of gravity, while the solidity ofthe dorsal spine gives advantage to the action of the head is terminated by a pointed bill, which aids in cleavingthe air; the feet, when short, are drawn up and concealed underthe feathers ; when long, they are stretched out beneath or behindthe tail, which is more or less expanded, and helps to support. Fig. 47.—Wing of Kamichi or Crested Screamer, the body in the air, as well as, by acting in the manner of arudder, to change its direction, or, by being expanded, to breakits descent. The wings of Birds (Figs. 45, 46, 47) are acute or obtuse. Themore angular the wing of birds—that is to say, the longer the featherson the edge of the wing—the more rapidly does it propel itselfthrough the air. The tail consists of a number of feathers, to whichare attached a series of small muscles, which are capable of depress- I/O REPTILES AND BIRDS. ing and elevating it in various degrees; while a series of connections,the fibres of which invest the base of the quills, curve round theedge. Their action is to spread out the tail-feathers, and inclinethem to the right or left; thus enabling it to perform the part of ahelm or rudder. Besides flight, Birds possess other means of locomotion, beingformed for walking, swimming, or flying, according as their habitsare aerial, terrestrial, or aquatic. T
Size: 2346px × 1066px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, booksubjectbirds, booksubjectreptiles, bookyear1
