The earliest of the forerunners of the horse with which we are acquainted would certainly not be recognized as such by any but the most careful student of animals, if we could see him to-day. He stood not higher than a fox-terrier dog, though his shape was very different. But he would probably be more likely to be classed with the dog than with the horse by the hasty observer, for he walked with four toes of each foot upon the ground as the dog does to-day. Like the dog, he had hanging at the inner side of his front foot a little useless toe. He was long in body, comparatively short of leg, a little long of head and neck, and distinctly long of tail. His grinding teeth had points on them not unlike a pig's, and possessed no apparent resemblance to the wonderful curved and ridged surfaces seen on the teeth of the modern horse. What his skin and hair were like can only be conjectured. In the restoration which Mr. Knight has made, at the suggestion of Professor Osborne, an interesting inference has been drawn. That he was a creature of the forest is suggested by his spreading toes, which would keep him from sinking in the soft soil. It is consequently surmised that he was dappled with spots which allowed him to rest unnoticed on the sun-flecked floor of the forest. Mane he had none, and his tail was probably tufted slightly at the end with hairs, which were increasingly short as they approached the top. He had no forelock, and the hair along the ridge of his neck was a little longer than the rest, and stood erect. Browsing about on the soft and tender herbage of his woodland home, his teeth had as yet no tendency to become specialized. The molars had mounds upon them, developing, perhaps, more into the shape of the points of the hog's, but even still quite generalized teeth. His main enemies, from whom, perhaps, he could with little difficulty escape, were creatures related to the hyenas of to-day. Perhaps, like their modern representatives, they preferred eating their flesh tainted to exerting themselves enough to capture and kill their prey. By the time we advance a little further into the Tertiary, though still in its early portion, a remarkable change has already come about. The fifth toe, which in the earliest horse hung upon the side of the front foot, has completely disappeared. The change in the hind foot has gone still further. The hind leg in many animals evolves more rapidly than the front. The heavy work of running is always done by the hind feet, while the front feet serve rather as a prop to keep the animal from falling than as the actual means of locomotion. Hence the hind feet and the muscles of the hind quarters are almost always heavier than the front. Possibly on the front foot the little fifth toe was less of an obstruction, and persisted after the early horse had lost the corresponding toe on his hind foot. This process has gone on still further in this second stage, and the hind foot has but three toes, while the front still