18 ASIA 



builds up an uninterrupted and massive system of parallel 

 folds extending from Assam to Yun-nan. 



The entire region, except the Malay Peninsula, lies 

 within the monsoon area, and is, therefore, characterized 

 by the annual rhythm of the dry and the wet seasons. 

 The rainfall is abundant and the temperature typically 

 tropical. It is therefore to be expected that vegetation, 

 while exhibiting tropical luxuriance, should reflect the 

 well-marked monsoon rhythm : this, however, is per- 

 fectly 'expressed only in part of the lowlands of Siam 

 and Burma. The landscapes which bear the stamp of the 

 monsoon are here : (1) the savana, corresponding with 

 that of the Sudan and South America. It is best repre- 

 sented on the low hinterland plateaus of Siam and Laos, 

 and to a less degree in Burma : (2) the drier and lighter 

 tropical forests which shed their leaves in the dry season. 

 Teak is, in eastern Asia, the typical tree of such forests : 

 (3) the jungle, a dry and tall deciduous scrub, some 

 thirty feet in height, which represents here the ' caatinga' 

 of Brazil. Besides these, and forming transitions between 

 the teak forest, the jungle, and the savana, occur count- 

 less varieties of light tropical woods, either evergreen or 

 deciduous, continuous or distributed in more or less 

 extensive patches. In fact, a great portion of what is 

 called jungle in Indo-China would be termed savana, 

 bush-savana, tree-savana in the Sudan or Brazil. 



The distribution of these monsoon formations seems 

 to depend largely on local circumstances of soil and 

 relief. The teak forests are best represented in the 

 upper inland plains and foot-hills of the Irawadi, as 

 well as on the marginal foot-hills of the middle Mekong. 

 Savanas and jungles are representative of lower Burma 

 and the low plateau of Siam, but their development is 

 limited both on the seaward and on the highland side 





