TRANSACTIONS OF SECTION E. 705 



These in turn control the distribution of plants and animals, in conjunction with 

 the direct action of surface relief, the natural regions and climatic belts dictating 

 the distribution of living creatures. A more complicated state of things is found 

 when the combined physical and biological environment is studied in its incidence 

 on the distribution of the human race, the areas of human settlement, and the 

 lines of human communications. The complication arises partly from the fact that 

 each of the successive earlier environments acts botli independently and collec- 

 tively; but the difliculty is in greater degree due to the circumstance that man 

 alone amongst animals is capable of reacting on his environment and deliberately 

 modifying the conditions which control him. 



It seems to me that the glory of geography as a science, the fascination of 

 geography as a study, and the value of geography in practical affairs are all due 

 to the recognition of this unifying influence of surface relief in controlling, though 

 in the higher developments rather by suggestion than dictation, the incidence of 

 every mobile distribution on the Earth's surface. 



The Classification of Geography , 



Following out this idea, we are led to a classification of the field of geography 

 in a natural order, in which every department arises out of the preceding with no 

 absolute line of demarcation, and merges into the succeeding in the same way 

 This classification, it is necessary to note, is not like a series of pigeon-holes, which 

 may be placed in any arbitrary order, but like a chain, in which the succession 

 of the links is essential and unalterable. 



Since form and dimension are the first and fundamental concepts in geography, 

 the first and basal division is the Mathematical. Mathematical geography leaves 

 the Earth as a spinning ball lighted and warmed according to a rigid succession of 

 diurnal and annual changes. This merges into the Aovaahioi Physical Geography, 

 which involves the results of contemporary change in the crust and the circulation 

 of the fluid envelopes, with the resulting modifications in the simple and pre- 

 dictable mathematical distributions. This division falls naturally into three parts : 

 Geomorphology, dealing with the forms of the solid crust and the changes they 

 are undergoing at the present time ; Oceanography, dealing with the great masses 

 of water in the world ; and Climatology, dealing with the efi'ects of solar energy 

 in the air. But all three spheres — lithosphere, hydrosphere, and atmosphere — are 

 so closely inter-related that no one of them can be studied without some preliminary 

 knowledge of the others. This forms the largest and most important part of 

 geography, more varied and intricate than the mathematical, better known and 

 more definite than those involving life. 



Bio-geography, the geographical distribution of life, arises directly from physical 

 geography, whicli dominates it, but it is full of complex questions which involve 

 the biological nature of the organism and the influence of physical environment, 

 in which geographical elements, although predominant, do not act alone. Difiicult 

 as some of the problems of the distribution of life are at the present day, the 

 remains of living creatures found fossil in the rocks, and the survivors of archaic 

 forms still lingering in remote islands, supply us with our only instrument of 

 research into the geography of past ages, often making it possible to lay down 

 the areas of land and water in earlier geological periods. 



The relation of man to the surface of the Earth detaches itself from the rest of 

 Bio-geography by the number of exceptions to general laws of distribution and by 

 the human power of modifying environment. It has necessarily been formed into 

 a special department, Anthropo-geography . In primitive man the control exer- 

 cised by environment is nearly as complete and simple as in the case of the lower 

 animals ; but with every advance in culture fresh complications are introduced. 

 The relation of people to the land they inhabit, the choice of sites for dwellings 

 and towns, the planning and carrying into effect of lines of communication, are all 

 obviously much under the control of land form and climate. When people get 

 settled in a favourable position they usually become attached to it ; they acquire, 

 one may say, the colour of the land, in modes of thought as well as in manner of 



