DOGS AND BEARS. 189 



here into the consideration of the well-marked differ- 

 ences in the structure of the soft internal parts of 

 these animals, or, indeed, of the greater part of the 

 skeleton, and we may therefore, in the main, confine 

 our attention to those of the skull and teeth, which, 

 as being the parts more commonly preserved in the 

 fossil state, demand the especial consideration of the 



FIG. 56. The Jackal. (From J (inline.) 



palaeontologist. There is, however, an important point 

 in regard to the bones of the fore-limb of carnivores 

 which cannot be passed over, namely, that in the arm- 

 bone or humerus of the cat tribe and some extinct 

 dog-like species the inner side of the lower end is 

 perforated by a small hole, which is totally wanting 

 in the corresponding bones of the dog and the bear, 



