so8 Mr. Carlisle on the Physiology of the Stapes. 
the air contained in the tympanum sufficiently to produce a 
sensible impression. 
That something like this occurs in many kinds of sounds is 
more than probable ; and as the cochlea consists of two hollow 
half cones, winding spirally, and uniting at their apices, it fol- 
lows that the sounds affecting either the cone terminating in the 
vestibulum, or that which forms the fenestra cochleae, must 
each pass from the wide to the narrow end ; and the tension 
of the parts, in either case, will necessarily aid the impression. 
I have already trespassed beyond the usual limits, and must 
reserve the more ample details of this subject for a work 
expressly directed to the anatomy and physiology of the 
organs of hearing. 
Explanation of Plate IV. 
a , The left* stapes of a human ear magnified two dia- 
meters; presenting the curved edge of the basis, and the 
more elevated and pointed arch. 
b, The opposite side of the same stapes, shewing its rounded 
arch. 
c , Two figures, the uppermost being the articulating sur- 
face of the capitulum, and the one beneath shewing the under 
surface of the basis, of the same stapes. 
d , Stapes of a hedge-hog, ( Erinaceus Europaus,) magnified 
four diameters. 
e, Stapes of a mole, (Talpa Europcea ,) magnified six times. 
f, Stapes of the musk ox, ( Bos moschatus,) twice magnified. 
* The other stapedes are all from the right ears. 
