162 THE HORSE AND ITS RELATIVES 



while the foldings of the enamel in all the cheek- 

 teeth are rather more complex than in the latter, 

 and the longitudinal diameter of the anterior pillar 

 is proportionately small. The first upper premolar, 

 or "wolf-tooth," is not infrequently developed in 

 the upper jaw. 



Professor Osborn adds that if the Arab is to 

 be considered specifically distinct from the horse 

 of Western Europe, it should bear the name Equus 

 africanus, which was applied by Sanson 1 in the 

 year 1869 to the Dongola breed. Professor Ridge- 

 way 2 has taken objection to that name, and pro- 

 posed to replace it by E. libycus or E. caballus libycus, 

 on the ground that the Dongola horse is a half- 

 breed, but such an objection is invalid. On the 

 other hand, there is an insurmountable bar to the 

 use of the name africanus owing to the fact that it 

 was employed by Fitzinger in 1857 as the designa- 

 tion of the African wild ass, for one of the races 

 of which, as will be seen in the sequel, it is still 

 used. There is, however, the name E. asiaticus, 

 proposed for the Arab by Sanson in the passage 

 cited, which is free from objection ; and that animal 

 may therefore be known either as E. asiaticus or 

 E. caballus asiaticus, according as to whether it is 

 regarded as a species or a race. 



In discussing the origin of the Arab, Professor 



1 Comptes Rendus A cad. Set. Paris, vol. clxix. p. 1205. 



2 The Thoroughbred Horse, p. 477, 1905. 



