Our adventurer starts with the following equipment of tools for making his arch as he learns to walk entirely on the ground which it must be remembered he can only do by unlearning _pari passu_ his highly cultivated power of grasping with his foot. The old and the new cannot flourish together. The evolving foot of man is an example of a slow change in the function of an organ and consequent modification of certain structures in it. He walks with his feet turning in, or in the axis of the leg; his great toe is not in this axis but may even lie at a right angle to the foot; he rests weight on his heel and even more on the outer border of his sole, and thus the sole of one foot turns more or less towards the other; and he puts a good deal of weight on his toes which are frequently doubled over; and his gait, though erect, is never completely so, and is clumsy in appearance. _Bones_: his heel-bone is relatively long and pointed and slightly arched below; the bones of his great toe are short and thick, and the other four toes relatively long and slender. You can see at once it is not primarily a walking foot. Any active boy of twelve could give him points and a beating in a race for life in the open. Further, his foot shows a much larger proportion of the whole foot in front of the end of the great toe than is ever seen in man. The _ligaments_ which bind the joints of his foot together, while the muscles play upon them, are little different from those he will require for the girders of his arch, except for such a throwing out of slips, and shifting under the stresses and strains of such walking as his new gait involves.