20 



OF THE EAR. 



Camper has figured tlie bone of the ear in the Northern 

 Sperm Whale, but I have not been able to refer to his figure, 

 and to compare it with the ear of our animal. Cuvier never 

 saw this bone of the sperm whale. In the Sydney specimen, 

 the external aperture of the meatus auditorius is so small as 

 only to admit of the entrance of a small quill. We may 

 suppose that the sense of hearing need not be very acute, if 

 Beale be right in contradicting the assertions of the old 

 writers on this subject, and denying to these animals the power 

 of making '^any nasal or vocal sound whatever." Never- 

 theless, the general opinion of whalers seems to be that the 

 Cetacea hear w ell, both in water and the open air ; and com- 

 parative anatomists, such as Professor E-ymer Jones, imagine 

 that, while aquatic sounds are received into the ear under 

 water by the external meatus, which, as above mentioned, is 

 reduced here to the smallest possible diameter — atmospheric 

 sounds, on the contrary, are perceived by the whale when his 

 snout is out of the water, by means of the blow hole, which 

 always communicates with the ear by a very wide Eustachian 

 tube. One of the well known characteristics of Cetacea as an 

 order, is to have the petrous portion of the temporal bone, 

 wherein is lodged the organ of hearing, more or less distinct 

 from the rest of the skull. In our whale the small bones of 

 the ear are consolidated into one irregular stony mass, which 

 is suspended by ligaments in a cavity formed between the 

 temporal, occipital, basilar, and sphenoid bones. It is an ear 

 diiferent from that of herbivorous Cetacea, and also from that 

 of true whales ; but, as Cuvier judged from Camper's figure, 

 remarkably close in its structure to that of the dolphin 

 family. It may be divided into two parts, the drum and the 

 labyrinth, which are separated from each other behind by a 

 very deep longitudinal hole. The labyrinth is a stony mass, 

 which may be divided into two portions, — 1st, the larger one 

 comprising the so-called semi-circular canals ; and 2nd, the 



