THE ARAB STOCK 163 



Ridgeway claims that India cannot have been the 

 home of the ancestral stock, owing to the fact that 

 during the historical period that country has been 

 unsuitable for horse-breeding. The Narbada valley 

 of Central India was, however, inhabited during 

 the Pleistocene, or latest geological epoch, and pro- 

 bably within the human period, by an extinct horse 

 {Egtciis na77iadicus\ while a second species {^E. 

 sivalensis) has left its remains in the some- 

 what older (Pliocene) deposits at the foot of the 

 Himalaya. Obviously, then, the argument that 

 India (which at the present day nurtures the 

 onager in Sind and Cutch) is unsuited to horses 

 applies only to part of the existing epoch. 

 Now the Siwalik horse agrees with the Arab 

 in the degree to which the facial part of the skull 

 is bent down on the basal axis, in the presence of 

 a preorbital depression, in the great relative width 

 of the upper premolars, and in the complexity of 

 the enamel-foldings in the centres of all the upper 

 cheek-teeth, and the shortness of the grinding- 

 surfaces of their anterior inner pillars ; the two 

 latter features being, indeed, more developed in the 

 extinct species than in the Arab, and thereby 

 approximating to the condition obtaining in the 

 extinct three-toed hipparion, as described in a later 

 chapter. The extinct species has also a large upper 

 wolf-tooth. 



I have therefore suggested the possibility of 



