4 ELEPHANTS, RECENT AND EXTINCT. 



the earth's history known as the Miocene ; but when we 

 have reached to that stage all below is dark as regards the 

 elephantine pedigree. And it is, indeed, one of the most 

 remarkable circumstances in palaeontology that although 

 we know that elephants belong to the great group of 

 Hoofed or Ungulate Mammals, of which they form a 

 well-marked division, yet we have practically no sort of 

 knowledge of the many extinct forms which we presume 

 must have connected them with Ungulates of a more 

 ordinary type. 



Although the trunk and tusks of elephants form their 



most striking external features, yet it is not to these that 



the naturalist looks at first when inquiring into the true 



affinities and general structure of these animals, since 



these come under the category of specialized and acquired 



structures, which tell but little of an animal's past history; 



he looks rather to the structure of the internal skeleton, 



which is always of especial value, as being that part of the 



organism which is usually alone preserved in a fossil state. 



Let us then first turn our attention to the skeleton of these 



animals, of which we may see examples in our larger 



museums. The most remarkable feature noticeable in such a 



skeleton is that the various long-bones of the limbs are 



placed almost directly one above another, so as to form 



nearly vertical columns of support for the body ; whereas in 



ordinary Ungulates, such as a horse or an ox, these bones 



are set very obliquely to one another. Moreover, as a 



similar vertical position of the limb-bones occurs in several 



old extinct Ungulates which are known to be of extremely 



primitive organization, we may take it that an elephant's 



limbs are likewise of a primitive type. We have, however, 



further evidence in confirmation of this primitive structure. 



Thus elephants differ from all other living Ungulates in 



having five complete toes to all their feet (Fig. 3). 



Moreover, whereas in other living Ungulates (except the 



little hyrax) the bones of the wrist are not situated in 



vertical rows immediately over the metacarpal bones of 



the foot, but, on the contrary, cross and overlap one 



another, in elephants they have the former relation, with 



the single exception that the bone marked I overlaps the 



