222 



SCIENCE 



N. S. Vol. XXX. No. 763 



The slender metacarpals from the valley of 

 the Arno and Auverg-ne so closely resemble 

 the Kent's Cave metacarpal and the teeth 

 from Perrier and Puy de Dome in France and 

 Lake Karar in Algiers so closely resemble the 

 small teeth from Oreston, that E. ligeris and 

 E. asinus atlaniicus may be regarded as 

 varieties or races of E. gracilis. 



There are good reasons for believing that E. 

 gracilis varied to form a northern and a south- 

 ern variety. Remains of a slender-limbed 

 northern race have been found in deposits be- 

 longing to the Neolithic, Bronze and still later 

 ages in Britain and on the continent. At the 

 present day the purest representative of this 

 northern variety is the " Celtic " pony. 

 Hence this northern variety may be known as 

 Equus gracilis celticus. 



Remains of a slender-limbed southern va- 

 riety have not yet been found in recent de- 

 posits in north Africa, but jSne-limbed ponies 

 without ergots and hind chestnuts are some- 

 times met with in the south of France, and 

 slender-limbed horses without hind chestnuts 

 — ^horses almost certainly of north African 

 descent — are occasionally met with in the 

 West Indies and Mexico. In the French and 

 still more in the wartless ponies of Mexico the 

 limbs are longer than in the Celtic ponies, the 

 coat is finer, the mane less- full and the " tail- 

 lock," so well developed in the northern va- 

 riety, is very small. As the southern variety 

 in all essential points agrees with Professor 

 Ridgeway's fine bay horse of north Africa 

 (E. caballus libycus) it may be known as E. 

 gracilis libycus. 



Slender limbs and the absence of ergots and 

 hind chestnuts, are apparently as distinctive 

 of members of E. gracilis as an upright mane 

 and the absence of hind chestnuts are distinct- 

 ive of asses and zebras. Hence when as a 

 result of crossing slender-limbed individuals 

 without ergots and hind chestnuts appear in 

 any area it may be assumed that the horses of 

 that area include E. gracilis amongst their an- 

 cestors. 



From enquiries made and from crossing ex- 

 periments, it has been ascertained that ponies 

 of the " Celtic " type occur in the Faroe Is- 



lands and Iceland, in the western islands and 

 highlands of Scotland, in the west of Ireland, 

 in "Wales, Exmoor and the New Forest and in 

 Norway and Finland. 



Further crossing experiments have made it 

 evident that the yellow-dun fjord horses of 

 Norway are mainly a blend of the " Celtic " 

 and " forest " types, that the Shetland ponies, 

 though usually having the conformation of 

 the " forest " or E. roiustus type, are in part 

 of Celtic origin, and that some of the mouse- 

 dun Tarpans of the Russian steppes are a 

 nearly equal blend of the Celtic and E. 

 przewalMi or " steppe " types. 



Professor Ridgeway arrived at the conclu- 

 sion that in the fine bay horse of North 

 Africa there is a frequent tendency to stripes 

 on the back, legs, shoulders and face, to a 

 blaze on the forehead and to white " brace- 

 lets." Experiments made with four types of 

 Arabs and with Russian, Mongolian, Indian 

 and Borneo ponies, English, Irish, Iceland and 

 Norse ponies, support the view that the Pleis- 

 tocene ancestors of the modern slender-limbed 

 ponies with short-pillared molars was of a yel- 

 low or bay-dun color with a narrow dorsal band 

 and bars on the legs, but had neither " brace- 

 lets " nor a blaze. 



As stripes are most numerous on broad- 

 browed horses with coarse limbs, they have 

 probably in most cases been inherited from 

 ancestors of the " forest " or E. robustus type. 



As to the part played by E. gracilis libycus in 

 forming domestic breeds, nothing very definite 

 has been made out. Professor Ridgeway says 

 all the improved breeds of the world are a 

 blend in varying degrees of the bay horse of 

 North Africa with thick-set, slow, dun and 

 white horses of Europe and Asia allied to E. 

 przewalshii. A number of hybrids bred at 

 Woburn by the Duke of Bedford afford little, 

 if any, evidence in support of the view that 

 Barbs, Arabs or thoroughbreds include 

 amongs their ancestors horses of the Pre- 

 jvalsky or " steppe " type. Slender-limbed 

 horses with a wide flat forehead and a nearly 

 straight profile appear to be a blend of E. 

 gracilis libycus (Ridgeway's E. caballus liby- 

 cus) and horses of the E. robustus (" forest ") 



