50 



THE MYOLOGY OF THE RAVEN. 



fact, however, to be kept before us is, that as the form 

 and tension of its walls vary, the tympanic membrane 



FIG. 19. Author's sketch of his dissection of the musculature of the air 

 passages of a Raven. Shown life-size upon lateral aspect, c.p., de- 

 tached portion of the costal process of the sternum, of the right side, 

 and turned about. 



which stretches across the mesial aspects of the bronchi, 

 upon the vibrations of which the voice of the bird 



