Chap. V] TROPICAL DISTRICTS WITH DRY SEASONS 363 



between the trees, which are further apart, also by its more marked 

 xerophilous character, and consequently by the greater abundance of 

 thorny and succulent plants. 



Thorn-woodland is also richly developed in the Antilles. It is very 

 extensive, for instance, on the east coast of Jamaica, where it consists in 

 particular of Mimosaceae and species of Cereus, and, as in Minas Geraes, 

 it appears to be confined to calcareous soil. Several of the smallest islands 





Fig. 195. Landscape at Lagoa Santa in Minas Geraes. On the ridges, savannah (campos) ; in the 



valleys, forest. After Warming. 



are almost completely covered by it, for example the Danish islands that 

 have been described by Eggers. 



3. TROPICAL GRASSLAND FORMATIONS, 

 i. GENERAL CHARACTER OF SA VANNAH. 



Whilst in regions with rain at all seasons of the year grassland plays 

 quite a subordinate part and owes its limited appearance to local influences, 

 in regions with marked dry seasons, especially in Africa and in South 

 America, it covers extensive areas, usually in the form of savannah, less 

 frequently in that of steppe. 



The appearance of a tropical savannah remains always essentially the 



