500 



ZONES AND REGIONS [Pt. Ill, Sect. II 



evergreen xerophilous broad-leaved trees appear hardly anywhere except 

 within the range of a mountain climate. Thus, for instance, as will be 

 shown in a later chapter, the)' form extensive bush-wood on the summits of 

 the mountains of the Malay Archipelago. Essentially different anatomical 

 adaptations on the part of the leaves, however, distinguish these plants from 

 the plants of the sclerophyllous woodland of the temperate lowlands with 

 moist winters. On the other hand, edaphic influences can determine the 

 colonization of neighbouring districts possessing different climates by the 

 sclerophyllous woodland. Thus, sclerophyllous plants clothe the sandy 

 dunes of the savannah-districts in the east of Cape Colony. Moreover, 



FlG. 26S. Sclerophyllous flora of the Mediterranean. Olive-trees at Nice. From a photograph. 



some few species, such as the laurel and box, have adapted themselves to 

 new climatic conditions, and appear as accessory constituents in the climatic 

 formations of other districts. Such cases, however, are of subordinate 

 importance, except in Australia, where sclerophyllous woodland has a very 

 extensive distribution. Many features render it probable that West Australia, 

 where the winters are moist and the summers dry, and where the sclero- 

 phyllous flora exhibits by far its greatest wealth, is the source from which 

 the other Australian districts have become colonized. 



Within the sclerophyllous districts grassland occurs at two places, namely in the 

 Sacramento Valley in California and in a part of South Australia. High temperatures 



