Reptiles and birds - a popular account of their various orders, with a description of the habits and economy of the most interesting (1883) (14565885357)

Identifier: reptilesbirds00figu (find matches)
Title: Reptiles and birds : a popular account of their various orders, with a description of the habits and economy of the most interesting
Year: 1883 (1880s)
Authors: Figuier, Louis, 1819-1894 Gillmore, Parker
Subjects: Reptiles Birds
Publisher: London : Cassell & Co.
Contributing Library: American Museum of Natural History Library
Digitizing Sponsor: Biodiversity Heritage Library



Text Appearing Before Image:
Fig. 67.Crop and digestive organs. DIGESTIVE ORG AXS. m seem to prove that they are attracted rather by the sight thansmell. The organ of sight is, indeed, more highly developed in birdsihan in any other class of animals. The volume of the eye itself is
Text Appearing After Image:
rig. 68.—Inljrnal Anatomy of BlcJi large compared with the head. It includes an addition which seemsto be confined to Birds. This is a black membrane, with many folds,yery rich in blood-vess.^ls, and situated at the bottom of the ocularglobe, and advancing towards the crystalline. Anatomy has failedto explain the use of this, but it is supposed that by enlarging cr i;8 REPTILES AND BIRDS. contracting it, birds obtain additional powers of vision. Other partsof the eye, such as the choroids, the thin membrane which coversthe posterior part of the eye, the iris, the retina, present nothing re-remarkable. The white of the eye is surrounded by an osseous orcartilaginous matter, evidently placed there for protection of thisdelicate and useful organ. Besides the ordinary upper and lower pupils, Birds possess athird. This consists of an extensive transparent membrane, dis-posed vertically, which covers the eye like a piece of network,protecting it from the effects of a blaze of light. It is