The structure of the shoulder and of the chest is full of interest. All the ribs are remarkably robust and of large volume, and, whereas in existing races they exhibit a flattened section, in the Neanderthals the section is distinctly triangular in form. This implies a very muscular and robust torso in correlation with the gigantic head and stout limbs. The collar-bones are correspondingly long, presenting a ratio to the humerus exceeding 54 per cent, which is much higher than that among the average existing races; this indicates a very broad shoulder. The shoulder-blade is also very different in type from that of the higher races of men, and even from that of the higher Primates; it is extremely short and broad. While, as noted above, the arm of the Neanderthals is relatively short and thus non-anthropoid, it presents a mingling of human and ape characters. The upper arm, or humerus, is truly of the human type, the torsion angle upon its axis being 148°, whereas in the anthropoid apes the angle of torsion never passes 141°. Among the bones of the lower arm the most significant is the radius, with which the turning movement of the hand is correlated; the structure of the head of the radius has more resemblance to that of the anthropoid apes than to that of existing species of man. The structure of the other bone of the forearm, the ulna, is also very primitive, exhibiting certain monkey characteristics. [Illustration: FIG. 122. Thigh-bones, or _femora_, of the Trinil, Neanderthal, and Crô-Magnon races, compared with one of modern type. The Neanderthal femur seems to be short and stout, whereas that attributed to _Pithecanthropus_ is relatively long, slender, and straight. Of the _femora_ illustrated the Neanderthal and Trinil are those of the type specimens, the Crô-Magnon is from the skeletal fragments of La Madeleine. After Dubois, Boule, Lartet, and Christy. One-eighth life size.] The structure of the hand is a matter of the highest interest in connection with the implement-making powers of the Neanderthals. The hand is remarkably large and robust, comparable in size with that of men of very large stature in existing races. With respect to the opposition power of the thumb against the fingers by means of the opponens muscle, a distinctively human characteristic, the stage of Neanderthal development is decidedly lower than that of existing races, because the joint of the metacarpal bone which supports the thumb is of a peculiar form, convex, and presenting a veritable convex condyle, whereas in the existing human races the articular surface of the upper part of the thumb joint is saddle-shaped, that is, concave from within backward, and convex from without inward. Thus the highly perfected motions of the thumb in _Homo sapiens_ were not attained in _Homo neanderthalensis_. Two phalanges which are preserved in the Chapelle-aux-Saints skeleton show that the fingers were relatively short and robust.