8 
Proceedings of Royal Society of Edinburgh. [sess. 
their recent ancestors, the majority of them probably have an 
unbroken chain of true wild ancestors. 
The existence in North- Western Europe of the Arab-like Celtic 
pony and in Central Asia of the long-headed Prejvalsky’s horse — 
forms quite distinct from the Equus caballus of Linnaeus, Gray, 
and other systematists — led me to feel less certain of the view 
provisionally adopted, well-nigh half a century ago, by Darwin, 
that all the existing races had descended “from a single dun- 
coloured more or less striped primitive stock.” 1 
The discovery, two years ago, in a remote part of the Western 
Highlands of Scotland of the remnant of a variety or species 
adapted for a forest life, made it impossible any longer to enter- 
tain the view that domestic breeds had all descended from a single 
post-glacial species. 
The conclusions arrived at during 1903 were in due time 
published in a paper entitled “The Multiple Origin of Horses and 
Ponies.” 2 In this paper I enumerated the chief characteristics of 
Prejvalsky’s horse and the Celtic pony, and indicated in what 
respects these types differed from the forest variety, 3 which, 
1 Animals and Plants under Domestication, vol. i. p. 65, 1875. 
2 Trans. Highland and Agri. Soc. Scot., vol. xvi., 1904. 
3 In a typical forest horse (PI. III. 9) the coat is of a dark yellow dun colour 
decorated by a broad dorsal band, remnants of stripes on the face, neck, shoul- 
ders, body, and loins, spots over the hind quarters and bars across the legs to a 
short distance below the knees and hocks, beyond which the legs are black ; 
the mane, forelock, and tail heavy, consisting of long dark coarse wavy hair — 
the tail having no tail-lock ; the hind as well as the front chestnuts large, 
prominent, and generally oval in form, and the fetlock callosities long and often 
curved ; the hoofs broad, rounded in front, and wide behind ; the head massive 
but well proportioned, the forehead broad with ridges extending from the 
prominent orbits towards the occipital crest, the profile convex from below 
the eyes to the level of the nostrils ; the upper lip long and prehensile, and the 
lower lip thick and often seen projecting beyond the upper ; the ears wide, of 
medium length, and usually carried upright ; the neck short and thick ; the 
shoulders straight, ending in broad flat withers ; the back hollow and long, 
owing to the presence of 24 dorso-lumbar vertebrae (18 dorsal and 6 lumbar) ; 
the hind quarters rounded so as to form a semicircle between the croup 
and the feebly-developed second thigh, with the tail inserted near the centre of 
the half circle ; tlie limbs short and strong with thick fetlock and knee- 
joints, the forelegs tied in at the elbow and back at the knee, the hind limbs 
straight and the hocks during action kept well apart. This horse is specially 
adapted for living in or near forests — for frequenting narrow paths, feeding on 
coarse grasses, leaves, twigs, and roots, and at need readily crossing swamps 
and clearing obstacles — by having prominent eyes, large teeth set in powerful 
