If we watch the progress of a bear over the surface of the ground, we readily perceive how lumbering is its gait and how poor the speed which it attains. Its slow and shambling movement is due to the fact that it has the tree-climbing foot, and is not well fitted for motion such as is required in running. To attain anything like speed in this exercise it is necessary to support the body on the tips of the toes. Every man who has gained any skill in this art knows full well how incompetent he is if he tries to run with rapidity in the flat-footed manner. The bear cannot essay this method of progression on the toe-tips because its loose-jointed feet cannot be made to support its heavy body. In this way arose the necessity of developing a peculiar kind of foot when that part had to serve for rapid locomotion. The experiments to this end have been numerous and varied. Thus in the elephants, which retain the originally numerous toes, the bones of these members are planted in an upright position and tied together with such strong muscles and sinews, that the foot parts have something like the solidity and strength of the upper portions of the legs. In the single-hoofed or horse-like forms, and in the cloven-footed animals, other series of experiments have been tried which in the end have proved most successful, giving us animals with the speediest movements of any animals except the creatures of the air. [Illustration: A Hunter] The success which has been attained in our ordinary large herbivora, and which has made them competent to evade the chase of the beasts of prey, has been accomplished by reducing the number of the toes, giving the strength of the aborted parts to increase the power of those remaining. The result is the formation of two great groups, the double-hoofed forms, including the pigs, deer, cattle, sheep, and their kindred, and the single-toed species, of which our horse is the foremost example. In the reduction of the number of toes, different plans were followed in each of these groups. In the cloven-hoofed forms, a single toe first disappeared, leaving but four; then the two outer of these were aborted, leaving two nearly equal digits. In the series of the horse, where we can trace the change more clearly, we find the earliest form five-toed, but the outer and inner digit shrunken so as to become of little use. This condition of the creature in the early Tertiaries gives us the beginning of the equine series, and shows that far away as the creature is now from ourselves, it originated from the main stem of mammalian life, from which our own forms have sprung. In the next higher stage in time, and likewise in development, we find these lessened toes at their vanishing point, and two of the remaining digits, lying on either side of what corresponds to the middle finger in our own hands, beginning to shrink in length and volume, while the central toe becomes larger and stronger than before.