400 T. H. St ruthers— Tertiary and Post- Tertiary. 



in its earlier and later stages glacial conditions differing in intensity- 

 affected a considerable area of both hemispheres, a temperate period 

 intervening. The method, compass, and force of the physical agents 

 in operation during each of its stages form intricate subjects of 

 investigation ; and the extent to which the processes in the newer 

 have overlapped, modified, or obliterated the geological features 

 of the older, is not generally agreed on; but much may be learned on 

 the subject of glacial agency from Dr. Archibald Geikie's " Scenery 

 of Scotland," and Mr. Jukes-Browne's " Building of the British 

 Isles," recent works of great merit. 



The Quaternary epoch was inaugurated by a reelevation of land, 

 which appears to have been effected by a series of sudden and 

 intermittent movements ; but a considerable period must have elapsed 

 before Europe was prepared for the reception of its first human 

 inhabitants ; and this, so far as that Continent is concerned, may be 

 regarded as a transition stage between Tertiary and Post-tertiary 

 time ; for the successive phases of organic and inorganic nature at 

 all periods of the earth's geological history passed from one to 

 the other, not suddenly and completely, but with the gradual change 

 of climatic and other physical conditions, and the successive extinc- 

 tion of organisms characteristic of the older, and the gradual 

 substitution of their successors in the newer order of things. 



The close of the " drift " introduces us into what Lyell calls the 

 Post-pliocene period, but which we denominate Pleistocene, when 

 the existing terrestrial areas which had been submerged were 

 developed and readjusted by repeated upheavals registered by a 

 series of geological landmarks well known to science, every successive 

 elevation increasing the extent of the low, fertile land, producing an 

 important alteration of the coast-line, and relatively reducing the 

 area under glacial conditions, which at last passed away, with certain 

 exceptions, under the combined influence of the local and general 

 physical causes by which climates are effected. 



Although Man found his way into Europe long before it had 

 attained its present development, when the climate was more 

 ungenial, it may have been a considerable time after the elevatory 

 movement began. This period of elevation, in the course of which 

 Man made his appearance in Europe, as already stated, we deno- 

 minate Pleistocene, as equivalent to Post-pliocene, and Post-glacial, 

 and descriptive of the oldest group of the Anthropozoic system. 

 This base line for the human period, however, must be understood 

 as provisional, for geological authorities differ in opinion as to 

 the particular stage of time which furnishes the earliest proofs 

 of Man's presence, some insisting that he was a denizen of 

 Europe during, or even before, the Great Ice Age ; but the evidence 

 in favour of this opinion is not so satisfactory as could be desired, and 

 there is ample room for additional proof; so that in the meantime 

 we may consider the question whether or not Man existed before, 

 or during, the Glacial period as unsettled. 



In the Pleistocene (Post-pliocene) period there were associated 

 with Man in Europe certain species of Tertiary mammals now 



