The Shetland Pony

by Charles Douglas; A. I. Douglas

The Shetland pony belongs to an ancient breed famed for its intelligence and docility, strength and hardiness, but especially remarkable because of its small size.

In a recent article on the Shetland pony it is said that “the highest authorities rather incline to the view that he is an instance of arrested development, and that all the equine race originally sprang from ancestors far more diminutive than the smallest Shetland.”

It is doubtless true that the remote ancestors of the Equidæ were small, but it does not necessarily follow that Shetland, Java, and other pigmy breeds owe their diminutive size to arrested development. A human pigmy of West Africa is as well developed as a Hottentot of South Africa, and a toy terrier is as well developed as a mastiff. There is hence no à priori reason for assuming that Shetland ponies are not as well developed—mentally and physically as perfect—as Clydesdales or Arabs. Moreover, all animals during their development repeat, more or less, their ancestral history, climb their own ancestral tree, hence if there is arrested development we should find evidence of reversion to more or less ancient types. Is there any evidence that in mind or body the Shetland is an instance of arrested development, or that he owes his diminutive size to reversion towards remote small ancestors?

It will be well at the outset to ascertain whether the small size is due to reversion or to dwarfing, induced, partly by unfavourable surroundings, partly by inbreeding and artificial selection.

The Size of the Shetland Pony.—Nature unaided has made a pigmy hippopotamus, pigmy elephants, and pigmy races of man, but there is no evidence that nature unaided in Europe or Asia in pre-glacial or post-glacial times produced a wild pigmy race of true horses—i.e., of horses with only one complete toe for each foot.

The smallest wild horses in Britain at the end of the Palæolithic period (i.e., according to a recent estimate some six thousand years ago) were apparently never under 12 hands at the withers. During the Bronze age, alike in wild and tame varieties, a size of at least 48 inches seems to have been maintained all over Europe. Further, remains from Roman military stations indicate that the smallest horses in Britain during the first century were probably never under 46 inches at the withers. It may hence be assumed that Shetland and other small breeds are not directly descended from pigmy wild races, but are the dwarfed descendants of one or more small varieties or breeds which had long lived under domestication.

A consideration of pigmy races makes it evident that dwarfing may be either equal or unequal, that it may result in the formation of a miniature having all the leading traits of the large race to which it belongs, or give rise to a pigmy variety in which certain parts are more dwarfed than others. In some small strains of dogs the relative proportion of all the parts are practically the same as in large strains, but sometimes in a small strain not only are the limbs more dwarfed than the trunk but certain parts of the limbs are more reduced than others. An example of unequal or disproportional dwarfing we have in the dachshund. In this breed the dwarfing has been carried further in the legs than in the body, and in the forearm than in the foot. In a normally constructed small hound in which the length of the body is 390 mm., the length from the elbow to the ground is 215 mm., from the elbow to the wrist 145 mm., and from the wrist to the end of the longest toe 95 mm. But in a typical dachshund with a body of approximately the same size (390 mm.) the length from the elbow to the ground is only 137 mm., the distance from the elbow to the wrist being 95 mm. and from the wrist to the end of the longest toe 90 mm.—i.e., in a dachshund, while the foot may only be reduced 5 mm., the reduction in the forearm may amount to 50 mm. (2 inches).

In the case of pigmy horses are the proportions of their normal ancestors invariably retained, or are the legs in some cases more dwarfed than the trunk, and as in the dachshund is the dwarfing greater in one part of the limb than in another? In Java ponies I have had under observation for some years the head and limbs bear practically the same relation to the body as in well-proportioned Arabs.

For example, in a 41-inch Java mare (fig. 1) the height at the withers, as in typical desert Arabs, is 2·7 times the length of the head, and the neck and limbs are relatively as long as in Arabs and other slender-limbed breeds.