CHAPTER I 

 ASIA 



The stupendous size and compact shape of this greatest 



of continents are features which by themselves are bound 

 to oxercise the strongest control on its vegetation by 

 determining the climate. The centre of this vast body 

 of. land is .so far removed from the regulating influences 

 of large Bheetsof water that it must, of necessity, be dry , 

 extreme in climate, and barren; ami life, whether vege- 

 table, animal, or human, must be reduced to a minimum. 

 Asia is a land of extremes. Broadly speaking, life is dis- 

 tributed, starting l'n>m a dead centre, in concentric belts 

 of increasing density. In this very general arrangement, 

 however, the fact of its excentric symmetry with re- 

 gard to the Equator introduces a first and fundamental 

 irregularity. 



The northern shores penetrate far into the polar 

 circle, while the southern coast is bathed by tropical seas. 

 All other things being equal, such a difference in the 

 amount of atmospheric heat is bound to be expressed by 

 a difference in the amount and the character of life on 

 the two sides. The exaggeration of summer heat and 

 winter cold of the atmosphere over the far inland parts 

 initiates corresponding movements of attraction and re- 

 pulsion of the surrounding masses of air, or, in other 

 words, large cyclones and anticyclones which have been 

 termed monsoons : the rhythmic alternation of these 

 forms the pulse of that vast body. As may be expected, 

 the inflowing summer winds are, on the whole, moist 



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