20 



the external aperture of the meatus aiuUtorius is so small as 

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

 that the sense of hearing need not he very acute, if Beale he 

 right in contradicting the assertions of the old writers on this 

 suhject, and denying to these animals the power of making " any 

 nasal or vocal sound whatever." Nevertheless, the general 

 opinion of whalers seems to be that the Getacea hear well, both 

 in water and the open air ; and comparative anatomists, such as 

 Professor Eymer 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 Getacea 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 

 different from that of herbivorous Getacea, 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 hemispherical 

 smaller one, which is separated from the larger portion nearly as 

 distinctly as in dolphins, and contains the cochlea. Three of the 

 four deep holes which separate these two portions of the laby- 

 rinth, are pierced at the bottom of the trefoil-shaped large one. 

 They serve for the admission of nerves. The tympanum or drum 

 is formed by a thick bony shell, curved inwards longitudinally, 

 so as to resemble the whorl of an univalve mollusc ; and to form 



