36 



THE ELEPHANTS. 



remains of the mammoth, and- even whole 

 carcasses with the flesh and skin, have been 

 found even in the most remote islands of the 

 Arctic Seas, and that this extinct species, 

 which furnishes us at the present day from 

 Siberia with much of the ivory of commerce, 

 was adapted, as is shown by its maned woolly 

 fleece, to much colder climates than those of 

 our temperate zone, while our still living 

 almost naked elephants are not met with far 

 outside the tropics. The presence of Quater- 

 nary elephants in the United States and in 

 Mexico perhaps finds its explanation in this, 

 that migrations of these animals took place 

 across Behring's Strait, a view supported 

 by the fact that on the islands and coasts 

 of this strait enormous accumulations of 

 remains have been found partly buried under 

 very old glaciers. 



The genus Mastodon is distinguished from 

 the elephants especially by its tuberculated 

 molars, by having more or less deciduous 

 tusks (incisors) in the lower jaw, and by the 

 absence of air-spaces in the frontal bones. 

 This remarkable genus appeared, in Europe 

 at least, at the time of the Middle Miocene 

 at Simorre and in Orleanais, and prevailed 

 chiefly during the time of the Upper Miocene, 

 when Europe rivalled India in the wealth of 

 species. The Pliocene witnessed a diminu- 

 tion in the number of species. At this stage 

 the genus died out in Europe and the whole 

 of the Old World, while it appears again with 

 the Pleistocene both in North and South 

 America, and evens exhibits several species 

 in the Quaternary strata of that hemisphere. 

 The great mastodon of the Ohio {Mastodon 

 giganteum) played a similiar r61e during the 

 Quaternary period in North America to that 

 played by the mammoth in the Old World. 

 The elephants have, without doubt, developed 

 from mastodons, for in spite of all the dis- 

 tinctions which we have mentioned, there are 

 yet transitional forms so closely related to 

 one another that we cannot but agree with 

 Gaudry in saying, " In reality it is impossible 



to say at what moment a tooth can no longer 

 be ascribed to a mastodon or must be ascribed 

 to an elephant." 



But while we remain confined to the region 

 of well -distinguished species, we must con- 

 clude from the fact above enumerated, that 

 the mastodons, having first appeared on the 

 mainland of the Old World, migrated to 

 America towards the close of the Pliocene, 

 and there continued to exist till the beginning 

 of the present period. 



The extinct genus Dinotherium deviates 

 most widely from the rest of the Proboscidea. 

 The skull so closely resembles that of the 

 sea-cows that many naturalists included the 

 animal in this order before the limbs were 

 discovered. The molars were ascribed by 

 Cuvier to a gigantic tapir, and lastly, the 

 enormous sabre-like tusks set in the down- 

 wardly curved lower jaw impart to the animal 

 a quite peculiar aspect. The bones of the 

 limbs discovered at Pikermi and in Bohemia 

 leave no doubt as to the true relationships 

 of the Dinotheria; they exhibit very close 

 affinities to those of the Mastodons. The 

 form of the molars with transverse ridges, 

 the so-called zygodont molars, can throw 

 little light on the affinities of the Dinotheria, 

 for this form is found also in the kangaroos, 

 manatees, and tapirs, as well as in our 

 elephants. The presence of large incisors 

 in the form of tusks in the lower jaw is 

 remarkable. The Mastodons, the oldest 

 proboscideans, have incisors in both jaws; 

 the elephants, their successors, have them 

 only in the upper jaw, and the Dinotheria 

 only in the lower jaw. The Dinotheria be- 

 came extinct at the close of the Tertiary 

 period. 



If we can trace back the ancestral stock 

 of our present elephants to the Miocene 

 mastodon of Simorre with narrow teeth, it is 

 impossible for us to pursue it to a more 

 remote antiquity. The mastodons, no doubt, 

 exhibit distant relationships to the ungulates 

 generally, and especially to the even-toed 



