446 ORDERS OF MAMMALIA. 



colder climate than either of the living species. This inference, 

 however, has been rendered a certainty by the discovery of the 

 body of more than one Mammoth embedded in the frozen soil 

 of Siberia. These specimens had been so perfectly preserved 

 that even microscopical sections of some of the tissues could 

 be made ; and in one case even the eyes were preserved. 

 From these specimens, we know that the body of the Mam- 

 moth was covered with long woolly hair. 



Amongst other Elephants which occur in Post-Pliocene de- 

 posits, may be mentioned, as of special interest, the pigmy 

 Elephants of Malta. One of these the Elephas Melitensis, 

 or so-called " Donkey-Elephant " was not more than four 

 and a half feet in height. The other the Elephas Falconeri, 

 of Busk was still smaller, its average height at the withers not 

 exceeding two and a half to three feet. 



The Mastodons in most respects closely resemble the true 

 Elephants, from which they are distinguished by their denti- 

 tion. As in the Elephants, the upper incisors grow from per- 

 manent pulps, and constitute long tusks; but in the majority 

 of cases the Mastodons also possess lower incisors as well. 



Fig. 364. Third milk-molar of the left side of the upper jaw of Mastodon 

 Arverntnsis, showing the grinding surface. Pliocene. (After Lyell.) 



The two lower incisors, however, though tusk-shaped, did 

 not develop themselves to any extent, and often disappeared 

 in adult life. A more important distinction between the Ele- 

 phants and Mastodons is that the molar teeth of the latter are 

 not only more numerous, but have the peculiarity that their 

 crowns are furnished with nipple-shaped eminences or tubercles 

 placed in pairs (fig. 364). The Mastodons appear to have 

 commenced their existence in the Miocene period, being re- 



