Then (B) the considerations militating against unquestioning acquiescence in that view were grouped in sequence, commencing with the difficulties introduced by the acceptance (in all its significance) of the Galley Hill skeleton. From an entirely different point of view (C), it was shewn that many difficulties may be solved by the recognition of more than one primordial stock of human ancestors. Lastly (F) came the modifications of theory necessitated by appeals to the powerful influence of physiological factors, acting in some cases quite obscurely, in others having relation to climate and food. The impossibility of summing up in favour of one comprehensive scheme will be acknowledged. More research is needed; the flatness of a cranial arc is but one of many characters awaiting research. At the present time a commencement is being made with regard to the shape and proportions of the cavity bounded by the skull. From such characters we may aspire to learn something of the brain which was once active within those walls. Yet to-day the researches of Professors Keith and Anthony provide little more than the outlines of a sketch to which the necessary details can only be added after protracted investigation. It is tempting to look back to the time of the publication of Sir Charles Lyell's 'Antiquity of Man.' There we may find the author's vindication of his claims (made fifty years ago) for the greater antiquity of man. In comparison with that antiquity, Lyell believed the historical period 'would appear quite insignificant in duration.' As to the course of human evolution, it was possible even at that early date to quote Huxley's opinion 'that the primordial stock whence man has proceeded need no longer be sought ... in the newer tertiaries, but that they may be looked for in an epoch more distant from the age of the Elephas primigenius than that is from us.' The human fossils at the disposal of those authors included the Neanderthal, the Engis, and the Denise bones. With the Neanderthal specimen we have (as already seen) to associate now a continually increasing number of examples. And (to mention the most recent discovery only) the Ipswich skeleton (p. 151) provides in its early surroundings a problem as hard to solve as those of the Engis skull and the 'fossil man of Denise.' But we have far more valuable evidence than Lyell and Huxley possessed, since the incomparable remains from Mauer and Trinil provide an interest as superior on the anatomical side as that claimed in Archaeology by the Sub-crag implements.