8zj< Mr. Home on the Organ of Hearing 
In my examination of the organ of hearing in this young 
whale, I find there is a peculiarity in its mechanism not met 
with in the smaller species of whale, and to which there is 
nothing similar in other animals. As this very singular me- 
chanism is not noticed by either Camper or Monro, and is 
only glanced at by Hunter, to whom it was imperfectly 
known, I shall give a description of it, and in doing so, men- 
tion the other parts of the organ, so far as will be necessary 
to make myself understood. 
The cranium had been deprived of the external skin, con- 
sequently the outward aperture of the ear had been removed ; 
a very small portion, however, of the external meatus could 
have been cut off, since the dark coloured cuticular lining, 
which is a continuation of the outward covering of the head, 
extended a little way into the tube. 
The meatus externus was five inches and a half long, and 
probably an inch had been cut off. Near this part the tube 
was one quarter of an inch in diameter, in the middle it vras 
narrower, and near the membrana tympani one inch and one- 
third of an inch. 
By comparing the measurement of the length of the tube 
with that of the skull in this whale, and with the large skull 
in the Hunterian Museum, the meatus externus in the full 
grown whale will be found to be about two feet six inches in 
length. 
The membrana tympani is one inch and one-tenth of an 
inch in diameter, where it is attached to the bone ; instead of 
being concave, as in other animals, towards the meatus exter- 
nus, it is convex, and projects nearly an inch into that tube. 
Its external surface is composed of a smooth firm cuticular 
