The progress of an evolutionary development is accordingly well-illustrated by these specimens. And although _Homo heidelbergensis_ is seen to be separated from his modern successors by great differences in form as well as a vast lapse of time, still the intervening period does provide intermediate forms to bridge the gulf. Not the least interesting of many reflections conjured up by the Mauer jaw, is that this extraordinary form should be met with in a latitude so far north of that corresponding to the Javanese discoveries. This difference, together with that of longitude, suggests an immense range of distribution of these ancestral types. Some of their successors are considered in the next chapter. CHAPTER II PALAEOLITHIC MAN The fossil remains described in the preceding chapter possess good claims to that most interesting position, viz. an intermediate one between Mankind and the more highly-developed of the Apes. From such remarkable claimants we turn to consider fossil bones of undoubted human nature. Of such examples some have been regarded as differing from all other human types to such an extent as to justify their segregation in a distinct species or even genus. Yet even were such separation fully justified, they are still indubitably human. In the early phases of the study of prehistoric archaeology, the distinction of a 'stone age' from those of metals was soon realised. Credit is due to the present Lord Avebury[9] for the subdivision of that period into the earlier and later parts known as the Palaeolithic and Neolithic stages. At first, those subdivisions possessed no connotation of anatomical or ethnical significance. But as research progressed, the existence of a representative human type specially characteristic of the palaeolithic period passed from the stage of surmise to that of certainty. Yet, although characteristic, this type is not the only one recognisable in those early days. In the following pages, some account is given of the most recent discoveries of human remains to which Palaeolithic antiquity can undoubtedly be assigned. The very numerous works relating to prehistoric man are full of discussions of such specimens as those found in the Neanderthal, at Spy, Engis, Malarnaud, La Naulette or Denise.