( m ) 
one for the Cochlea, ( Fig, X. ( h) and two for the 
FemflreB ( b,c.) 
The Cochlea is a long Cavity confiding of three 6'^res 
or Meanders ; f Fig. XI. {de f) Its Orifice where it pro- 
ceeds from the Vefiihtlum is but fma!] ; but it afterwards 
widens, fo that the firft courfe of this Cavity is a third 
part larger than the fecond ( e), and proportionally 
the third is lefs than the odier two {f), till it termi- 
nates in an Orifice ( g ) fituated in the Top, for receiv- 
I ing a branch of the loft portion of the Nervus Audi- 
tortus, which accompanies and pafles along all its G)res. 
The hardnefs and folidity of the Bone (for which 
I it may be juflJy called Os Petrofnm in this Subjeff^ was 
I fuch that 1 could not fo exadly trace the three Ca- 
I nals or Duds of the La^rinth, fo as to give a true I- 
I dea of the manner of their feveral Turnings. But Fal- 
falva’s Figures of the Humane Ear direded me fo ex-' 
adly, that I eafily found out the feveral Orifices, and 
opened them fo far as to find out their fituation and 
true Dimenfions, by introducing a Hogs bridle, then 
cutting it off and ftretching it out to the Scale. Thus 
after laying open the two Foramina which gave an inlet to 
the Vefiihulum, I foon perceiv’d the feveral Orifices 
which in fo large a Subjed were pretty confpicuous. 
I firft turn’d to the one hand and difeovered the Du6l 
of the Cochlea ; this I purfued all along the Protube- 
rance, {Fig.Wl, ( d) \n doing of which 1 laid wholly 
open the Leffer Du6l of the Lal'jrinth ( Fig. IX. {d ) 
Then turning up the other fide of the Bone, I trac’d 
the (oft Portion of the Nervus Auditorius divided into 
two Branches, one whereof was diftributed into the 
Cochlea, and the other to the Lal'irinth. Tn filing the 
Bone a little further, I opened a fmall part of the Mid- 
dle DuH, and in a^fiiorc time I difeovered 
Major-' °t. 
