32 THE STRUCTURE AND LIFE OF BIRDS chap. 



Fig. 33. {a) Human ear— diagrammatic ; (?>) ear of Owl, after Gadovv ; (c) of 



Thrush, after Retzius. 



c, Columella ; cch, Cochlea ; e, Eustachian tube ; ex, outer opening of Ear ; 



L, Labyrinth; Lg, Lagena ; m, Membrane, closing the drum ; n, entrance of auditory 



nerve; nn, Nerve endings; 01, 2, 3, the three Ossicles, Stapes, Incus, Malleus; 



ft, Pterygoid bone. 



