MODIFICATION OF THEORY EXAMINED. 127 



In the preceding chapter, I have endeavoured to 

 show that physical principles do not warrant such a 

 conclusion. I shall now proceed to consider what the 

 direct testimony of Geology and Palaeontology is on 

 the subject ; and I believe we shall find that the facts 

 of Geology and Palaeontology are as much opposed to 

 the conclusion as are the principles of Physics. 



On this point I may quote the evidence of a 

 geologist who, more than any other, has devoted 

 special attention to all points relating to Glacial and 

 Interglacial periods. Prof. J. Geikie, after devoting 

 upwards of five hundred pages of his "Prehistoric 

 Europe" to the consideration and accumulation of 

 facts from all parts of this country and the Continent 

 relating to Glacial and Interglacial periods, gives the 

 following as the result of his investigations : — 



" We note," he says, " as we advance from Pliocene 

 times, how the climatic conditions of the colder epochs 

 of the Glacial Period increase in severity until they 

 culminate with the appearance of that great northern 

 mer cle glace which overwhelmed all Northern Europe, 

 and reached as far south as the 50th parallel of lati- 

 tude in Saxony. Thereafter the glacial epochs decline 

 in importance, until, in the Postglacial Period, they 

 cease to return. The genial climate of Interglacial 

 ages probably also attained a maximum towards the 

 middle of the Pleistocene Period, and afterwards 

 became less genial at successive stages, the temperate 

 and equable conditions of early Postglacial times being 

 probably the latest manifestation of the Interglacial 

 phase." * 



I shall now quote the same author's description of 

 an Interglacial Period as demonstrated by its flora 

 and fauna. The reader must, however, observe that, 



* "Prehistoric Europe," p. 561. 



