5£2 



APPENDIX. 



spine, terminating in a point, require more than a 

 skin being laid over them in order to give the re- 

 gular and characteristic form of the animal. 



The bones of the anterior extremity give no 

 idea of the shape of a fin, the form of which 

 depends wholly upon its covering. The differ'- 

 ent parts of the skeleton are so inclosed, and 

 the spaces between the projecting parts are so 

 filled up, as to be altogether concealed, giving the 

 animal externally an uniform and elegant form, 

 resembling an insect enveloped in its chrysalis 

 coat. 



The bones of the head are in general so large, 

 as to render the cavity which contains the brain 

 but a small part of the whole ; while in the human 

 species, and in birds, this cavity constitutes the 

 principal bulk of the head ^. This is, perhaps, 

 most remarkable in the Spermaceti Whale; for on 

 a general view of the bones of the head, it is im- 

 possible to determine where the cavity of the skull 

 lies, till led to it by the foramen magnum oc- 

 ciptale. The same remark is applicable to the large 

 Whalebone and Bottle-nose Whale ; but in the 

 Porpoise, where the brain is larger in proportion 

 to the size of the animal, the skull makes the 

 principal part of the head. 



Some of the bones in one genus differ from 

 those of another. The lower jaw is an instance 



* In the Porpoise however, the head of which bears a consider- 

 able resemblance to that of a bird, the brain is extremely large, 

 and much resembles the human. 



