43 2 Mr. Hunter’s Obfervations on the 
particular kind, being white, ligamentous, and each part rather 
rounded than having flat fldes *. One of the flnufes palling 
out of the tympanum dole to the membrana tympani, goes a 
little w r ay in the fame direction, and communicates with a 
number of cells. 
The whole funclion of the Euftachian tube is perhaps not 
known ; but it is evidently a duel from the cavity of the ear, 
or a pafl'age for the mucus of thefe parts ; the external opening 
having a particular form would incline us to believe, that fome- 
thing was conveyed to the tympanum. 
The bony part of the organ is very hard and brittle, ren- 
dering it even difficult to be cut with a law, without its chip- 
ping into pieces. That part which contains the immediate or- 
gan is by much the hardefl, and has a very lmall portion of 
animal fubftance in it; for when fleeped in an acid, what re- 
mains is very foft, almofl: like a jelly, and laminated. The 
bone is not only harder in its fubftance, but there is on tho 
whole more lolid bone than in the correlponding parts of qua- 
drupeds, it being thick and mafly. 
The part containing the tympanum is a thin bone, coiled 
upon itfelf, attached by one end to the portion which contains 
the organ ; and this attachment in fome is by clofe contact 
only, as in theNarwhale; in others, the bones run into on© 
another, as in the Bottle-nofe and Piked Whales. 
The concave lide of the tympanum is turned towards the 
organ, its two edges being clofe to it; the outer is irregular, 
and in many only in contact, as in the Porpoife : while in 
i 
* Thefe communications with the Euftachian tube may be compared to a large 
bag on the bafes of the lkull of the Horfe and Afs, which is a lateral fwell of 
the membranous part of the tube, and when diftended will contain nearly a 
quart. 
others 
