382 PHILOSOPHICAL TBANSACTIONS. [aNNO 17 18. 



COW ; though if we consider their contracts with brewers for grains, their rent 

 of grounds which lay useless, servants wages, &c. their real loss may, by a 

 modest computation, be allowed to be lOl. for every cow that died. 



^ Description of the Organ of Hearing in the Elephant^ with the Figures and 

 Situation of the Ossicles, Labyrinth, and Cochlea, in the Ear of that large 

 jinimal. By Dr. Patrick Blair, R. S. S. N^ 358, p. 885. 



In the description I formerly wrote of the elephant I dissected in Dundee, 

 Anno 1706, and inserted in the Philos. Trans. N'* 226, 227, I treated of the 

 bony part of the ear of that prodigious animal a little too superficially ; because 

 I was unwilling at that time to break up the os petrosum of the right ear, which 

 had accidentally been separated on dividing the skull, by which the account I 

 then gave of the lineae semilunares, or labyrinth and cochlea, was rather lame. 

 But I have chosen since rather to destroy that bone than that the public should 

 be deprived of an exact description of that curious organ ; and that I may give 

 a clear idea of all its bony parts, I shall repeat what I formerly advanced oa 

 that subject, and add what improvements I have made on it since. 



The meatus auditorius is a long straight tube situated horizontally, and 

 reaching from the outer to the inner table of the skull, not unlike the barrel 

 of a pistol, but somewhat oval, the sides of the cavity are hard and solid, about 

 the thickness of a halfpenny, and from the outer part several of the laminae 

 between the 2 tables of the skull arise, fig. 8, pi. 9 : its cavity is an inch or ^ of 

 an inch diameter, and length Q-^ inches; being somewhat enlarged as it arrives 

 at the crena for the membrana tympani. Fig. 9. 



This crena is 2 inches in circumference, within which is the cavitas tympani, 

 consisting of 2 different surfaces; the one much deeper and cellulous, the other 

 more superficial and smooth. The first runs perpendicularly down 4- inch from 

 the crena tympani. Its bottom is variously divided into several cellules, not 

 unlike a honeycomb, but irregularly disposed. Its bony laminae, by which 

 these cellules are distinguished from each other, are thicker at the top than at 

 the bottom, being about \\ line distant from each other, and about \ inch 

 deep. 



Besides the use of these two cavities, to receive and discharge the superfluous 

 moisture, they are also most beneficial and assisting to the hearing; for, no 

 sooner is the external air modulated, and the membrana tympani moved by it, 

 than the sound is conveyed by the ossicles to the nervus auditorius, and the 

 undulation continued, first by the anfractuosities of the first cavity, and then 

 by the gyres and incurvated lines of the second; so that we may easily account 

 for the acute sense of hearing with which elephants are said to be endowed. 



