ILLUSTRATIONS. 



No. ' Page 



1. Carrier Pigeon (Columba tabellaria) . . 13 



2. Eyes of the Eagle, showing their great size in proportion 



to the head 22 



3. Plan, in section, showing the general structure of the Ear 33 



4. Inside of the temporal bone, showing the position of the 



drum and bones of the Ear, surrounded by the 

 mastoid cells ....... 34 



5. Tympanum and bones of the Ear . . . .35 



6. Bones of the Ear . . . . . .36 



7. Sections of the Cochlea . . .37 



8. External view of the Cochlea and semicircular canal . 37 



9. Section of Cochlea and semicircular canals . . 37 



10. Distribution of nerves in. semicircular canals . . 38 



11. Distribution of nerves in Cochleaand semicircular canals 38 



12. Head of the Horned Owl (Strix otus) . . 40 



13. Skull of the Horned Owl, showing the auditory canal . 41 



14. Skull of the Hare, showing the auditory canal . . 43 



15. Skull of the Polecat, showing the auditory tube . . 43 



16. Skull of the Fox, showing the auditory hole . . 46 



17. Structure of the Ear of the Owl . . . .46 



18. Drum of the Ear in Birds (enlarged from Dei-ham's 



figure) 47 



19. Toucan (Ramphastos toco) . . . . .64 



20. Portion of the upper surface of the human tongue, show- 



ing the nervous papillae, magnified 100 times . 84 



21. Upright section of the nervous papillae, magnified 400 



times ........ 85 



22. Tongue and head of the Ostrich (Strut/tio camelus) . 86 



23. Tongue and head of the Toucan (Ramphastos toco) 88 



