Page:Natural History, Birds.djvu/186

Rh fluid than those of any other birds; for Professor Owen found that air passed into the extreme bones of the wing, and into the joints of the toes. The eyelids are fringed with stout and stiff lashes, the object of which may be to protect the eyes



from particles of dust and rotten wood falling on them, when engaged in excavating decayed trees for the purpose of incubation. The Crotophaga, whose beak presents an analogy to that of the Hornbills, has the eyes similarly protected: this bird, however, does not excavate trees.