ARABS AND THOROUGHBREDS. 19 



the forehead may be regarded as the typical colour, although grey 

 is by no means uncommon ; and the mane and tail are always 

 long, pendent, and full. The fetlocks of one or more legs are 

 not un frequently white. 



The skull generally, if not invariably, shows a slight depression 

 in front of the socket of the eye (fig. 18, pf.), which although 

 now serving as the attachment for the muscle running to the 

 nostril, probably represents the cavity which almost certainly con- 

 tained a face-gland in the skull of the extinct Hipparion. Many 

 of the dark-coloured Horses of Europe have Barb or Arab blood 

 in their veins, this being markedly the case with the Old English 

 Black, or Shire Horse, the skull of which accordingly shows a 

 distinct depression in front of the eye-socket (fig. 17, pf.). That 

 the face-gland may well have disappeared in modern Horses is ex- 

 emplified by Sheep, the domesticated breeds of which possess this 

 structure, although it is lost in the wild American Bighorns. In 

 the latter the place where the gland should be situated is probably 

 occupied by muscle. As two instances are known to the w^riter 

 in which modern Horses (one an Argentine) have developed 

 functional face-glands, on one or both sides, there is not much 

 doubt that the depression seen in the skulls of Arabs and 

 Thoroughbreds represents the pit for the tear-gland of Antelopes 

 and Deer (fig. 5). 



Prof. W. Ridgew^ay regards bay us the typical colour of the 

 Arab. This is confirmed in some degree by the fact that grey Arabs 

 when aged tend to become flecked with chestnut ; and also by 

 the circumstance that some grey Arabs are slate-coloured or 

 mouse-coloured when young. 



A considerable number of skulls are placed on exhibition to 

 illustrate the presence of a vestige of the facial gland- cavity in 

 the skulls of Arabs and Thoroughbreds, and its general absence 

 in those of other breeds, except Shires. 



The skulls of Arab Horses are further characterised by the 

 long interval between the first upper cheek-tooth and the outermost 

 incisors, as well as by the relatively small size of the upper cheek- 

 teeth, the length of the six cheek-teeth in the skull of " Jerboa " 

 (N.H. 9) being only 6f inches, while the basal length of the 

 skull itself is 19f inches, or nearly the same as that of the 



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