THE MAMMALIA. 37 



have survived to sit as artist's model to primitive man. But 

 allowing that the Mammoth died — say, of regret that the Glacial 

 period was passing away — what killed the Mastodon and the 

 Deinotherium ? The Mastodon survived the Post-Pliocene times; 

 the Deinotherium grew tired of a naughty world in one short 

 Tertiary period, the Miocene. Yet, apparently, it might have 

 found swamps to its heart's content down to the present day. 



Three species of extinct elephants appeared in the Upper 

 Miocene of India alone, where certainly there were no climatic 

 conditions to interfere with their continuance. They ranged over 

 Britain, Europe, Asia, and North America. They are found of all 

 sizes, some being no bigger than goats or donkeys. The pigmy 

 elephant of Malta was four feet and a-half in height, and the 

 Elephas Falconeri of Busk was still smaller, its average height not 

 exceeding two and a-half to three feet. But they have passed 

 away just like their larger brothers. One is often tempted to 

 think that unwieldy size is one of the factors in the extinction of 

 species ; but evidently the tiny elephant of Busk did not perish 

 for that reason. 



From the Proboscidea, we come to the most primitive of all 

 surviving Ungulata, the Camel, of which there are but two 

 closely-allied Hving species, the two-humped Bactrian camel and 

 the dromedary, a native of the deserts of Arabia. The true camels 

 appear with startling suddenness in the Old World. They are 

 found developed precisely as they are now in the Siwalik Hills of 

 India. But the genus Camelidae (camels and llamas) appears 

 with an immense wealth of species in North America. Pro- 

 camelus only differed from the existing camels in having four prae- 

 molars on each side of the jaw instead of three. The family 

 history of the Camelidce is as perfect and almost as interesting as 

 that of the horse. Their earliest-known ancestor seems to have 

 been the " Miocene Foebrotherium, in which the bones of the foot 

 had not coalesced, and the mouth was furnished with a complete 

 set of incisor teeth, through Protolahus, whose incisors are present 

 in full number, but fall out readily ; Procamelus, with incisors like 

 those of our present camel ; and metatarsals (bones of foot), 

 which have coalesced and become the 'canon-bone'; and finally, 

 Pliaiichenia and Auchenia^ leading up to the present llamas. A 



