ABSTRACT
The working together of head and hand in all the operations by which man has won his place in the world is apparent to everybody. The anatomist and the neurologist are impressed with the nice complexity of the structures by which head and hands are connected. The embryologist watches with never-ceasing wonder the structures gradually come into being properly ordered for making the completed organism. Anatomists and embryologists have dwelt at length on the fact that the human form presents many structures which are primitive in character. Man at the very dawn of his career as man had physical members which he could spare from other uses and by which he could take hold of such external objects as sticks and stones, and move them about to his pleasure, and shape them to some extent the better to serve his needs.
