592 
NATURE 
[APRIL 21, 1904 | 
of the knees and hocks. In all three varieties the mane is 
short and upright in the autumn, but leng enough in 
spring to arch to one side of the neck; in summer the 
upper two-thirds of the dock of the tail carries short hair, 
the distal third long hair, which continues to grow until 
it reaches the ground; in winter the upper two-thirds of 
the tail carries hair from 2 to 4 inches in length. The hair 
of the body and limbs is short in summer, but under the 
jaw and over the greater part of the body and limbs it is 
from 3 to 4 inches in length in winter. 
The hoofs are narrower and have longer “ heels ’’ than 
in the common horse, but, as in the common horse, each 
limb is provided with a chestnut and with an ergot, the 
hind chestnut (hock callosity) being very long and narrow. 
In the variety (Fig. 4) occurring in the Altai south of 
Kobdo—probably the most primitive of the three—the head 
is large and coarse, and, compared with the length of the 
body, longer than in any domestic breed. In a side view 
it is noticed that the forehead is prominent (bumpy), the 
lower part of the face straight or slightly convex, the under 
lip long, and that the head forms nearly a right angle 
with the short neck. The eyes are lateral in position, and 
appear unusually close to the ears owing to the great length 
of the space between the eye and the nostril. The ears are 
long and generally project obliquely outwards (Fig. 4), as 
in many cart-horses. The croup is nearly level, but .the 
hocks are usually bent and turned in. Judging by the 
behaviour, during the Jast two years, of the wild horse 
in my possession, I am inclined to think his less remote 
ancestors, though in all probability members of the steppe 
fauna, lived for a time (perhaps during the Ice age) in the 
vicinity of forests. As is the case with other gregarious 
animals, he strongly objects to be separated from his com- 
panions, and he also objects to have his movements circum- 
scribed by fences. It has often been said ‘ nothing jumps 
better than a cart colt.’’ The cart colt jumps because he 
has sprung from big-jcinted, broad-hoofed, forest-haunting 
ancestors whose existence often depended on their being 
able at a bound to clear fallen trees and other obstacles. 
The wild horse when shut up in a loose-box by himself is 
very restless, and keeps rearing up against the door until 
set at liberty ; if placed in a paddock away from his special 
comrades he generally succeeds in either scrambling over 
or breaking down the fence. 
The wild horse never encounters fences in the Gobi desert, 
but, probably because he had forest-bred ancestors which 
had often to cross fallen trees, he endeavours without a 
moment’s hesitation to clear all obstacles that come in his 
way, while true desers forms endeavour to- break through 
them. 
It has been suggested that the wild horse of the Gobi 
desert is not a true wild animal, but only a domesticated 
breed that has reverted to the wild state. Against this 
view I may mention (1) that all the wild horses are of a 
yellow-dun colour, and that though those to the west of 
Kobdo differ in tint from those to the east, the eastern and 
western varieties seem to be connected by the less specialised 
variety to the south of Kobdo; (2) that travellers in Central 
Asia all agree in stating that the Mongclian ponies vary 
greatly in colour—in a Chinese hymn known as_ the 
““Emperor’s Horses’? as many as thirteen colours are re- 
ferred to; (3) the descendants of the horses which escaped 
from the Spaniards in America after several centuries of 
freedom were of all sorts of colours; and (4) in horses which 
live in sub-Arctic areas the hair at the root of the tail-tends 
to increase so as to form a sort of tail-lock, which when 
caked with snow protects the hind-quarters during snow- 
storms; the complete absence of this tail-lock—fairly well 
developed in one of my Mongolian ponies—is a very strong 
argument against the assumption that Prjevalsky’s horse 
is nothing more than a domesticated breed that has reverted 
to the wild state. 
” 
The wild horse of the Gobi desert is certainly the least 
specialised of all the horses living at the present day. In 
being of a yellow-dun colour, in shedding annually the hair 
of the mane and the hair from the upper two-thirds of the 
tail, in having ergots and chestnuts .on the hind- as well as 
1 Tt was formerly stated that the wild horse was simply a hybrid betweena 
Mongolian pony and akiang. I recently showed that a hybrid of this kind 
is quite different from the wild horse. See Proc. Roy. Soc. Edin., vol. xxiv. 
part v., 1902-1903, and NaTuRE, vol. Ixviii. p. 271. 
NO. 1799, VOL. 69 | 
on the fore-limbs, and in having canines and fairly large - 
upper first premolars, Prjevalsky’s horse is distinctly 
primeval. Only in the all but complete absence of stripes 
and in having very long powerful jaws armed with relatively 
large teeth can the Gobi horse be said to be specialised. 
It is extremely probable that Prjevalsky’s horse was 
familiar to the troglodytes who inhabited the Rhone valley in 
prehistoric times. One might even go further and say that 
in Fig. 1, from an engraving in the cave of La Mouthe, 
we have a fairly accurate representation of the head of 
Pijevalsky’s. horse. i 
It is, of course, impossible to say which of the. recent 
breeds are most intimately related to the Gobi horse, 
Though the head and ears are suggestive of some of thé 
heavier occidental breeds, in its trunk and limbs it more 
closely resembles Mongolian and Korean horses, some of 
which, like Prjevalsky’s horse, decidedly differ from Shires 
and Clydesdales in having a small girth owing to a want 
of depth of body. To which domestic breeds the wild horse 
has contributed characters will probably become more 
manifest after he has lived for some time under domestic- 
ation. That heavy occidental breeds are not pure de- 
scendants of Prjevalsky’s horse is suggested by the fact 
4 : ‘ Sed 
Photograph by AM. H. Hayes. 
Fic. 4.—Prof. Ewart’s yearling wild horse in summer coat. 
(From Hayes’ ‘*‘ Points of the Horse.’’) 
that cart-horses, like zebras, have usually Six lumbar 
vertebrae—the wild horse of Asia has only five, like the wild 
asses. 
Tue CeLtic Pony (Equus caballus celticus). 
From the most primitive member of the Equida family 
I shall turn to the most specialised, viz. to what I have 
ventured to call the Celtic pony. 
In colour 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 
round the eye, and a more distinct dorsal band. The hair 
is similar in structure, but slightly longer in the Celtic 
pony during winter (Fig. 5), more especially under the jaw 
—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 Gobi horse. 
The mane is made up of a mesial portion (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 
