PHYSIOGRAPHIC PROBLEMS OF TO-DAY 647 



going modifications. The wide extent of the changes in progress, 

 and their known importance in certain instances, are justification 

 for the belief that the physiographer as well as the ecologist will 

 find many problems of fundamental importance to his science in 

 the interrelations of life and physiographic conditions. 



Physiography and Man 



Go forth, subdue and replenish the earth, is the language of Scrip- 

 ture. The observed results show that, while man strives to bend 

 nature to his will, he himself is a plastic organism that is moulded 

 by the many and complex external forces with which it comes in 

 contact. Here again two groups of themes present themselves to 

 the physiographer: one embracing the influences of environment 

 on man; and the other, the changes in the features of the earth's 

 surface, brought about by human agencies. In the first the phy- 

 siographer can aid the anthropologist, the historian, the socialist, 

 etc.; and in the second, which is more definitely a part of his own 

 specialty, he searches for suggestive facts throughout the entire 

 domain of human activities. It is in these two directions that the 

 student of the earth's surface finds the most difficult and the most 

 instructive of the problems in which he takes delight, and the richest 

 rewards for his efforts. 



The control exerted by physiographical environment on human 

 development is so subtle, so concealed beneath seemingly accidental 

 circumstances, and its importance so obscured by psychological con- 

 ditions, that its recognition has been of slow growth. The countless 

 adjustments of both the individual man and of groups of men in com- 

 munities, nations, and races, to physical conditions, is so familiar 

 that the sequence of causes leading to observed results passes as a 

 matter of course, and to a great extent fails to excite comment. The 

 due recognition of the influence of physiographic environment on 

 history is now coming to the front, and, as is evident, the rewriting 

 of history, and especially the history of industry, from the point of 

 view of the physiographer, is one of the great tasks of the future. 

 The problems in this broad field are countless, and the end in view 

 is similar to those embraced in dynamical physiography, namely, 

 the study of the various ways in which man is now influenced by 

 his physical environment, with the view of interpreting the records 

 of similar changes in the past and of predicting future results. 

 Or more definitely formulated: peoples have reached a high degree 

 of culture under certain multiple conditions of environment, while 

 other peoples, exposed to other combinations of conditions, have 

 remained stationary, or retrograded and become degenerate. What 

 are the essential conditions in control in the one case or the other? 



