In considering the limbs, the differences between the arms and hands of man and those of anthropoids are apparent, but less striking than in the case of the lower limbs. For the prehensile foot of apes has in it something abnormal which distinctly differs from the human foot, adapted for walking. Nor can the prehensibility of the human toes in certain cases be directly compared with the prehensibility of an ape’s foot, in which the great toe has the action of a thumb. Haeckel remarks that newly born children can also take a strong grip with the great toe, and if a spoon is inserted they can hold it with the foot as firmly as with the hand.[129] This power is, however, only partial and subordinate, compared with the manifold and developed prehensibility of an anthropoid’s foot. The possibility of walking upright to a certain, although sometimes to a very limited, extent is no exclusive privilege of anthropoids, since this power may be acquired by training in the case of other apes, as well as of dogs, pigs, horses, etc. Many apes of the New World, such as the tailed and climbing apes, as well as some semi-apes, bears, ichneumons, scaled and rodent animals, can go for some distance in an upright position, quite as readily as anthropoids, and without being trained to do so.[130] The structure of anthropoids is, indeed, better adapted for going on all-fours, or for climbing. The projection of the coccyx in the form of a rudimentary tail has, as is well known, been observed in some isolated cases in the human species. This peculiarity is supposed to be hereditary in the case of some non-European peoples, such as the Niam-Niam of Central Africa, and some of the Southern Malays. But this surmise has not yet been confirmed.