The teeth, according to Dubois, are unlike the teeth of either men or apes, but according to Virchow and Hrdlička, they are more ape-like than human. The femur, though unquestionably man-like, might conceivably belong to an ape of the gibbon type, inasmuch as the upright posture is more normal to the long-armed gibbon than to any other anthropoid ape, and its thighbone, for this reason, bears the closest resemblance to that of man. According to the “Text-Book of Zoölogy” by Parker and Haswell, the gibbon is the only ape that can walk erectly, which it does, not like other apes, with the fore-limbs used as crutches, but balanced exclusively upon its hind-limbs, with its long arms dangling to the ground—“The Gibbons can walk in an upright position without the assistance of the fore-limbs; in the others, though, in progression on the surface of the ground, the body may be held in a semi-erect position with the weight resting on the hind-limbs, yet the assistance of the long fore-limbs acting as crutches is necessary to enable the animal to swing itself along.” (_Op. cit._, 3rd ed., 1921, vol. II, p. 494.) The Javanese femur is rounder than in man, and is, in this, as well as other respects, more akin to the thighbone of the gibbon. “After examining hundreds of human femora,” says Dubois, “Manouvrier could find only two that had a somewhat similar shape. It is therefore a very rare form in man. With the gibbon a similar form normally occurs.” (_Loc. cit._, pp. 456, 457.) Whether the thighbone really belonged to an erectly walking animal has not yet been definitely settled. To decide this matter, it would be necessary to apply the Walkhoff x-ray method, which determines the mode of progression from the arrangement of the bone fibers in frontal, or other, sections from the femur. This test, however, has not hitherto been made. Nor should the significance of the fact that the thighbone was found at a distance of some _fifty feet away_ from the skull-cap be overlooked, seeing that this fact destroys, once and for all, any possibility of _certainty_ that both belonged to the same animal.