The general reception of Prof. Geikie’s book was deferential if not enthusiastic. The masterly handling of the subject was freely admitted, and the thorough and scholarly manner in which the sources of information had been searched; but no symptoms appeared to indicate the existence of a school of advanced interglacialists, in Britain at any rate, prepared to accept and defend the author’s theoretical views. In fact, for a time it almost seemed as if the belief in the reality of interglacial periods, or at least in their importance, was less prevalent than it had been fifteen years before. A very large body of geologists declined to regard the evidence on which Prof. Geikie and his supporters relied as having real value or significance. There were still a few supporters of the theory of the marine origin of boulder-clay, and even some who were prepared to advocate the agency of floods and debacles as the prime factors in the formation of boulder-clay; and their views for some years were prominent in the discussion of the origin of glacial deposits. The majority of experienced geologists certainly did not accept these explanations; but they were equally unwilling to concede that the Ice Age could be subdivided into six glacial epochs, alternating with warmer climates in which Northern Europe and America had been occupied by a fauna and flora of temperate facies. Prof. Geikie lived to see very considerable changes in the opinion of geologists on these matters. As time went on much new evidence accumulated to prove that great fluctuations of climate had marked the recent stages of the earth’s history. From many sides facts were reported which tended to support his theories. Gradually it came to be recognised that the ice margin must have withdrawn at times for considerable distances, leaving bare wide tracts of country which became populated by animals and plants. Still, however, it was contended that these were mere episodes of no great account, temporary retreats and advances of the ice-sheets, unworthy to be designated glacial and interglacial periods. But the increase of knowledge renders this position less and less tenable as years go by, and it may fairly be claimed that before Prof. Geikie’s death, in most countries of Europe and North America the existence of several interglacial periods was freely conceded by a majority of those who were competent to express an opinion on the subject.