LESSER CEREBRO-SPINAL LYMPH 121 



gland, takes place here in connection with the foramen 

 ova/e (Figs. 43, 44) and saccule, where there is frequently 

 found a collection of otoliths or crystals, pointing to the 

 operation of similar producing factors on similar fluids, or 

 crystal-containing media. 



Before concluding, we perhaps ought to call attention to 

 the fact that analysis of the fluids here mentioned, viz. the 



FIG. 43. DIAGRAMMATIC VIEW FROM BEFORE OF THE PARTS COMPOSING 



THE ORGAN OF HEARING OF THE LEFT SIDE. (After Arnold. ) 



The temporal bone of the left side, with the accompanying soft parts, has been 

 detached from the head, and a section has been carried obliquely through it so as 

 to remove the front of the meatus externus, half the tympanic membrane, and 

 the upper and anterior wall of the tympanum and Eustachian tube. The meatus 

 internus has also been opened, and the bony labyrinth exposed by the removal 

 of the surrounding parts of the petrous bone, i, the pinna and lobe ; 2 to 2', 

 meatus externus ; 2', membrana tympani ; 3, cavity of the tympanum ; above 3, 

 the chain of small bones; 3', opening into the mastoid cells ; 4, Eustachian tube ; 

 5, meatus internus, containing the facial (uppermost) and auditory nerves ; 6, 

 placed on the vestibule of the labyrinth above the fenestra ovalis ; a, apex of the 

 petrous bone ; b, internal carotid artery ; c, styloid process ; d, facial nerve 

 issuing from the stylo-mastoid foramen ; e, mastoid process ; f, squamous part of 

 the bone. 



cerebro-spinal fluid, and the otic, peri-, and endo-lymph, so 

 far as we have been able to discover, yield substantially 

 the same chemical results, or, at any rate, attest that these 

 results do not differ more from each other than the results 

 obtained by different analysts do from each other when 

 examining the same fluid, and to claim that we are 

 justified in hazarding the opinion that a common chemical 



