690 MAMMALIA [CH. 



' The Horse, as we know it, has been domesticated and bred by 

 man for thousands of years and is doubtless very unlike its wild 

 ancestor, but there is some evidence that this wild ancestor still 

 exists as Equus przewalskii, a small species of Horse with large head 

 and bristly mane, which still roams over the steppes of Central 

 Asia. An excellent specimen of this species could formerly be seen 

 by visitors to the London Zoological Gardens. It showed a consider- 

 able resemblance not only to pictures of Horses found on remnants 

 of ancient pottery but to existing breeds of Horse found in isolated 

 parts of Northern Europe, such as the Icelandic Pony and the 

 " Hest " of "Western Norway. It had a peculiar tail which consists 

 of a bushy wisp of comparatively short hairs as in the modern Horse ; 

 but from the centre of this bunch a tassel of very long hairs hangs 

 down. Rude drawings of Horses with tails just like this are found 

 on the flint tools of early man. The Zebras and Wild Donkeys 

 have longer ears than the Horse, and they afe all more or less 

 striped ; they have not got the peculiar wisp-like tail of the Horse. 

 Such animals are found in Africa on the great plains in the south, 

 in the deserts of Syria and Persia and in the central plains of India. 

 Another African form, the Quagga, has become extinct in recent 

 times. In America when discovered there were no Horses, although 

 the Horse has since run wild there ; but in the most recent geological 

 period the Horse abounded in America and why it should have died 

 out in a country which afterwards proved to be well suited for it 

 is a mystery. In the same country in the deposits formed on 

 ancient alluvial plains are found the remains of a series of animals 

 which form a complete chain from a true Horse which appears 

 in the newest deposits to animals which are like Tapirs but which 

 are even more primitive since they retain a vestige of the thumb on 

 the hand and a trace of a fourth toe in the foot. This series of 

 forms is one of the most complete evidences of evolution known to 

 geologists, and it seems clear that the evolution of the Horse must 

 have taken place in this part of America. 



Division II. ARTIODACTYLA. 



f 



Unlike the Perissodactyla, the Artiodactyla or even-toed Un- 

 gulates constitute an immense assemblage of animals, and until the 

 invention of modern fire-arms they were the dominant animals on 



