446 THE MULTIPLE ORIGIN OF HORSES AND PONIES, 



storm. The iHoinent the stonii set in the pony orientated herself so 

 that the snow was driven against her hind (piarters. In a few min- 

 utes the lock of hair was spread out to form a disk, to wdiich the snow 

 adhered, and tlius provided a shield which effectually prevented the 

 flakes findinii' their way around the root of the tail, where they would 

 have soon melted and effectively chilled the thinly clad inner surface 

 of the thighs. Provided with a caudal shield, long, thick hair over the 

 hind quarters and hack, and a thick mane covering both sides of the 

 neck and protecting the small ears, a Celtic pony is practically snow 

 proof. While the storm lasted the pony in question stood perfectly 

 still, with her head somewhat lowered, save when she shifted her posi- 

 tion as the wind veered from northwest to north. Very different was 

 the behavior of an Aral) and a thoroughbred Highland colt close by. 

 After trying various attitudes the Arab, carrying her head low and to 

 one side, made a rush for the shelter of an adjacent wood; the half- 

 bred colt — prevented by her Celtic blood from running away — tried 

 in vain one })osition after another, and long before the storm ceased 

 looked thoroughly miserable and began to shiver as if chilled to the 

 bone. It hence follows that the tail lock is not, as I at first assumed, 

 an inheritance from a primitive ancestor akin to the wild horse, but 

 a highly specialized structure which eminentl}^ adapts the Celtic pony 

 for a subarctic environment. I need hardly say the caudal fringe is 

 not a product of artifical selection, for even in Iceland, where it reaches 

 its maximum development, neither its existence nor its use has, so far 

 as I can gather, ever been referred to. It need only be added that to 

 maintain a tail lock of this kind it is necei^sary that the short, wiry 

 hairs of which it consists must be renewed once a year. 



In separating asses and zebras from horses, stress has hitherto 

 been laid on the difference in the mane and tail, and especially on 

 the absence of hind chestnuts. As already j^ointed out, the wild 

 horse during summer in its mane and tail agrees with asses and 

 zebras. The mane and tail are hence no longer of specific impor- 

 tance. This is also true of the chestnuts, for in the Celtic pony, 

 as in asses and zebras, the hind chestnuts (hock callosities) are com- 

 pletely absent. In the wild horse, as in the vast majority of heavy 

 and cross-bred horses, the hind chestnuts reach a considerable size, 

 but in asses and zebras and the Celtic pony I have failed to find any 

 rudiments of hind chestnuts, either l)efore or after birth. Further, 

 in the Celtic pon}^ the front chestnuts are small, and, still more 

 remarkable, tJie fetlock callosities (ergots) have entirel}^ vanished; 

 in asses and zebras the ergots are always present, and in some cases 

 still play the part of pads. The Celtic pony is hence not only more 

 specialized — further removed from the primitive type — in its mane 

 and tail, but also in having lost the fetlock pads (ergots) and the 

 hock (heel) callosities. Nature makes little effort to get rid of use- 



