the level of the neighbouring teeth, and there is no "diastema" or gap in either the upper or lower row of his teeth.[9] There is no trace of such a gap nor any excess of size of the canines in any living race of men, and what is more remarkable, the jaws of very ancient prehistoric men which have been found in the Middle Pleistocene--the Neander or Moustierian men as well as the more ancient jaw from Heidelberg (see p. 286)--do not show any difference in this respect from the most advanced European race. On the other hand, it is one of the most remarkable features presented by the recently discovered "Piltdown" lower jaw that it had a larger canine tooth than that of any recent or fossil man, and consequently a gap or "diastema" in the row of teeth (see Chap. XXX). This difference between men and apes is all the more marked since the grinders or cheek teeth (called also molars) of man and the higher apes agree very closely, each to each in order of their position, in the pattern formed by the irregular surface of the crown. There are some slight differences in relative size and in the order of their "cutting" or growth, but these are trivial. The jaws of man show their derivation by gradual dwindling from the larger projecting jaws seen in apes and monkeys, in the close setting (that is to say, "crowding") of the teeth, and also in the dwindling and late "cutting" of the last tooth, in each jaw above and below, which we call the wisdom tooth. The "wisdom teeth" are in the higher races of men on their way to total disappearance. In lower races of men they are larger than in the higher, and in the man-like apes are of full size, and there is plenty of room in the jaw for them. [9] See Plates VII. and VIII., p. 166, in "Science from an Easy Chair," Second Series, for careful drawings of the complete series of teeth in both the upper and lower jaw of Man and of an Ape.