( 268 ) 

 TABLE XXXIII. 



Systematic Survey of the Development of the Ilumaii Ear. 

 I. Survey of the parts of the Internal Ear. (Apparatus perceptive of sound.) 



'1. Stalk of the primary 1. Aqueduct of the Aqucrductus vestibiili 



ear-vesicle vestibule {Due- s. Btcassus lahyrintki 



tus endAjlytii- 

 phaticus) 



2, 3. Upper part of the 2. Ear-pouch Utriculus 



p. imary ear-vesicle 3. Tiiree senii-circu- Canalts semi-circu- 



Products of the ^ 



Hom-plate 



B. 



Products of the 



Head-plate 



lar, or curv..d 

 canals 



4, 5. Lower part of the 4. Ear-sac 



primary ear- vesicle 5. " The snail " 



/ 6. Auditory nerve 



6. Auditory nerve 



lares 



Saccului 

 Cochlea 



If^ervus acusticus 



7. Bony covering of the 7. Osseous labyrinth Labyrinthui osscus 



membranous laby- 

 rinth 



8. Bony covering of the 8. " The stony bone " Os petrosuin 

 I whole internal ear 



II. Survey of the parts of the Intermediate and External Ear. (Apparatus for the 



conveyance of sound.) 



C. 



l*roducts of the 

 first 



Gill-opening 



9. Inner part of the first 

 gill-upening 



10. Central p irt of the first 

 gill-opening 



].l. Closed part of the first 

 gill-opening 



/12. Upper part of 



the 



Products of the 

 first two 



Gill -arches 



E. 



Prod act of the 



Head-plate 



Product of the 

 Skin-covpring 



second gill-arch 



13. Upper part of the first 



gill-arch 



1 4 . Cen tral part of the fiist 



gill-arch 



J 15. Tympanic circle 



j {Aniiulus tympanicus) 



16. Circular membranous 

 fold at the closed part 

 of the first gill- 

 opeuicg 



9. Eustachian tube Tuha Eustachii 



10. Tympanic cavity Cavum tympani 



(Interior of the 

 drum) 



11. Tympanic mem- Jkmbrana tynqiani 



brane (Head of 

 the drum) 



12. Stirrup (First Stapes 



bonelet of the 

 ear) 



13. Anvil (Second Inous 



bonelet of the 

 ear) 



14. Hammer (Third Mallctcs 



bonelet of ihe 

 ear) 



15. Bony outer audi- Meatus cuditoriu; 



tory passage osseus 



16. Ear-shell 



Conclia auris 



17. Rudimentary ear- Musculi conc\Kr 

 muscles 



