It was at one time the ambition of some breeders to have Shetland ponies as small as their remote three-toed Miocene ancestors. As a matter of fact, ponies smaller than some of the Miocene species have long existed in Shetland. Eric, though an average-sized pony, was at least a hand smaller than the late Miocene horse, _Protohippus sejunctus_, in which the front cannon-bones (fig. 9_b_) were 177 mm. long and 21 mm. wide—_i.e._, 34 mm. (1·37 inches) longer but 5 mm. narrower than in Eric; while Seedpearl (31·75 inches at the withers) and other still smaller living ponies have shorter limbs than the very ancient three-toed _Mesohippus_ from the Badlands of South Dakota. But while some Shetland ponies are actually smaller and have relatively decidedly shorter legs than the horses which flourished long before man appeared on the scene, they never have three toes and their teeth are always decidedly longer if not more complex than in the most advanced Miocene species. Hence, as already said, though in Shetland ponies there is evidence of arrested growth, there is no evidence of arrested development. It has been pointed out that the facial part of the skull of Eric is so short that the frontal index is extremely high—67 instead of 54. Even more remarkable than the shortening of the face is the reduction in Eric of the capacity of the nasal chambers. In new-born foals, owing to the relatively large size of the cranium, the face is always more or less dished (fig. 7). In the case of the wild horse of Mongolia, the increase in the size of the nasal chambers soon gets rid of the dishing, and in course of time the nasal bones are bulged outwards, so as to give rise to a more or less marked “Roman-nose” (fig. 8). But in Eric and many other Shelties of the riding or Celtic type, owing to the expansion of the nasal chambers being prematurely arrested, the profile in the adult (fig. 6) differs but little from that of the new-born foal (fig. 7). _Shetland Ponies of the Cart-horse or “Forest” Type._—For want of material nothing very definite can be said about the nature of the dwarfing of ponies of the heavy or cart-horse type. In a typical 12-hands Celtic pony the metacarpals are 200 mm. long, 27·5 mm. wide, but in a typical 12-hands “forest” horse the metacarpals are, on an average, 193 mm. long and 35·1 mm. wide. An undwarfed, thick-set, 36-inch Sheltie built on the same lines as a 12-hands “forest” horse should have metacarpals about 145 mm. in length and 26·4 mm. in width, and should measure 5·5 inches below the knee.