THE MULTIPLE ORIGIN OF HORSES AND PONIES. 445 



ircsted by the fact tliat cni-t horses, like zebras, have usually six 

 luuibar vertebrae — the wihl horse of Asia has only five, like the wild 

 asses. 



THE t'Ei/nc I'oNv {Equus eahallus celticiis). 



From the most primitive member of the Pjcjuidse family I shall turn 

 to (he most specialized, viz, to what 1 have ventured to call tlie Celtic 

 pony. 



In color and markings a typical Celtic pony only differs from the 

 intermediate (Altai) variety of the wild horse in having a slightly 

 darker muzzle, a less distinct light ring ai-ound the eye, and a more 

 distinct dorsal band. The hair is similar in structure, but slightly 

 longer in the Celtic ])ony during winter (fig. 2, pi. i), more espe- 

 cially under the jaAv — where it forms the so-called beard — over the 

 hind quarters, and on the legs. In the mane, tail, and callosities the 

 Celtic pony is very different from the wild Gol)i horse. The mane is 

 made up of a mesial poi'tion (nearly twice the width of the entire 

 mane in an Arab) consisting of strong dark hair, and of two lateral 

 portions the hair of which is lighter and finer and less circular in 

 section than the hair of the central portion. The mane in the adult 

 grows at the rate of from 9 to 10 inches per annum, and as only about 

 one-third of the hair is shed annually, the mane reaches a consid- 

 erable length. Owing to the great width of the middle portion the 

 one-half of the mane generally falls to the right side, the other to the 

 left. The front jiart of the mane hangs down over the face to form 

 a forelock (fig. 2, pi. i). 



The most remarkable feature of the Celtic pony is the tail. To 

 begin with, the dock is relatively very short — so short that one is apt 

 to suppose it has been docked. The distal two-thirds of the dock 

 carries long dark hairs, the majority of which continue to grow until 

 (hey trail on the ground. During winter and spring the proximal 

 third of the dock (about 4 inches) carries stiff hair from 3 to (3 inches 

 in length, which forms what may be known as a caudal fringe or tail 

 lock (fig. 2, pi. I and fig. 1, pi. ii). In the case of Arabs and other 

 semitropical horses, the first 1 or 2 inches of the dock are usually cov- 

 ered with short, fine hair like that over the hind quarters, but in the 

 Celtic pony fine, wiry hairs from 4 to 5 inches in length extend right 

 up to the root of the dock under cover of the body hair of the croup. 

 The most distal hairs of the tail lock overlap, but are quite distinct 

 from, the long ])ersistent hairs carried by the lower two-thirds of the 

 dock. The hair in the center of the fringe, of the same color as the 

 dorsal band (fig. 1. pi. ii), projects obliquely backward; the hair at 

 the sides is light in color and i)rojects obliquely outward. The pres- 

 "ence of this very remarkable l)unch of hair at the root of the tail was 

 quite incomprehensible until I noticed what happened during a snow- 



