342 GEIKIE 



one of its main lines of advance must be in the direction 

 of what may be termed geographical evolution. The geog- 

 rapher will no longer be content to take continents and 

 islands, mountain chains and river valleys, table-lands and 

 plains, as initial or aboriginal outlines of the earth's surface. 

 He will insist on knowing what the geologist can tell him 

 regarding the growth of these outlines. He will try to 

 trace out the gradual evolution of a continent, and may 

 even construct maps to show its successive stages of de- 

 velopment. At the same time, he will seek information 

 regarding the history of the plants and animals of the 

 region, and may find much to reward his inquiry as to 

 the early migrations of the fauna and flora, including 

 those even of man himself. Thus his pictures of the living 

 world of to-day, as they become more detailed and accurate, 

 will include more and more distinctly a background of by- 

 gone geographical conditions, out of which, by continuous 

 sequence, the present conditions will be shown to have 

 arisen. 



I propose this evening to sketch in mere outline the 

 aspects of one side of this evolutional geography. I wish 

 to examine, in the first place, the evidence whereby we 

 establish the fundamental fact that the present surface of any 

 country or continent is not that which it has always borne, 

 and the data by which we may trace backward the origin 

 of the land; and, in the second place, to consider, by way of 

 illustration, some of the more salient features in the gradual 

 growth of the framework of Europe. 



The first of these two divisions of the subject deals with 

 general principles, and may be conveniently grouped into 

 two parts: ist, The Materials of the Land. 2d, The Build- 

 ing of the Land. 



I. GENERAL PRINCIPLES OF CONTINENTAL EVOLUTION 

 i. The Materials of the Land 



Without attempting to enter into detailed treatment of 

 this branch of the subject, we may, for the immediate pur- 



