( 268 ) 

 TABLE XXXIII. 



Systematic Survey of the Development of the Human Bar. 

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



1. Stalk of the primary 1. Aqueduct of the Aqumductus vestibuli 



ear- vesicle vestibule (Due- s. Recessus laln/rinthi 

 tus endolym- 

 phaticus) 



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



primary ear-vesicle 3. Three semi-circu- Canales semi-circu- 



Products of the .< 

 Horn-plate 



B. 



Products of the 



Head-plate 



lar, or curved lares 

 canals 



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



primary ear- vesicle 5. "The snail" 



Sacculiu 

 Cochlea 



6. Auditory nerve 6. Auditory nerve Nervus acusticus 



7. Bony covering of the 7. Osseous labyrinth Labyrinthus osseus 



membranous laby- 

 rinth 



8. Bony covering of the 8. " The stony bone " 0$ petrosum 



whole internal ear 



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

 conveyance of sound.) 



Products of the 

 first 



Gill-opening 



D. 



Products of the 

 first two 



Gill 'arches 



E. 



Product of the 



Head-plate 



Product of the 

 Skin-oovering 



/ 9. Inner part of the first 

 gill-opening 



1 . Central pa rt of the first 



gill-opening 



11. Closed part of the first 



gill-opening 



/12. Upper part of the 

 second gill-arch 



13. Upper part of the first 



gill-arch 



14. Central part of the first 



gill-arch 



15. Tympanic circle 



. (Annulus tympanicus) 



9. Eustachian tube Tuba Eustachii 



10. Tympanic cavity Cavvm tympanx 



(Interior of the 

 drum) 



11. Tympanic mem- Membrana tympani 



brane (Head of 

 the drum) 



12. Stirrup (First Stapes 



bonelet of the 

 ear) 



13. Anvil (Second Incus 



bonelet of the 

 ear) 



14. Hammer (Third Malleus 



bonelet of the 

 ear) 



15. Bony outer audi- Meatus cuditoriui 



tory passage osseus 



16. Circular membranous 16. Ear-shell 

 fold at the closed part 

 of the first gill- 

 opening 



Concha auris 



17. Rudimentary ear- Musculi concha 

 muscles 



