The arms of man are relatively shorter and his legs much longer than in the man-like apes. The Neandermen were more ape-like in these proportions than are modern races of man, and show also an "ape-like" curvature of the thigh bone which in man is straight. Whilst the arm and hand of man has gradually become a more delicate thing than that of the apes, and capable of much greater variety and efficiency in the movements of its parts, this condition has come about by alteration in proportions and to some extent shape, and not by any great change in construction. Only two muscles exist in connexion with man's hand not found in that of the higher apes. They are small slips adding to the efficiency of the fingers and thumb, whilst in the foot there is in man a small muscle connected with its outer border--"the peroneus tertius"--which helps to keep the sole of the foot turned downwards, and is not present in the apes. The general shape and proportionate size of the muscles of the leg in man give it a very different appearance from that of the ape; but there are no muscles or bones present which are not found in the apes. The beautiful outline and form of the human leg and buttocks are directly the result of the increased size of certain muscles used in maintaining the upright position, and in the peculiarly human swing of the leg in walking and running. Their beauty, like that of the other specially human features which we consider beautiful, depends upon the fact that their development, in due proportion, is a necessary condition of efficiency, activity, and strength in movements and attitudes which have gradually been acquired by man, and distinguish him from the apes. Our admiration for them is a sort of self-love, a worship of an ideal of efficiency and balance which is specifically "human," and is more or less fully realized in every individual. Probably sexual selection has had a large share in thus moulding the human form. The apes do not present the development of the gluteal region characteristic of man, and the muscles of both the arms and legs in them are, though very powerful, less fleshy and more "stringy" than those of man. There is, indeed, a difference of "quality" in the muscles of apes and men, especially civilized men, which needs investigation by the microscopist and experimental physiologist.