AN (ECOLOCtICAL SUHVP]V OF THl-] MIDLANDS OF NATAL. 528 



Sum:i\iary for Bqsh Formation. 



This midland type of bush differs slightly in its composition 

 from the similar bush on other terraces. The bush nearer 

 the coast is more nearly allied to tropical East A.f rican forest. 

 Though many of the species composing the midland bush 

 also extend through the tropics, yet some of them do not, and 

 many that do so extend are confined to the mountains in the 

 tropics.. 



In its general oecological character the close type of bush in 

 Natal may be taken as intermediate between sclerophyllous 

 woodland, such as occurs on the west of South Africa (where 

 there are winter rains and dry summers) and tropical rain 

 forest. Some of the trees are more xerophytic than others, 

 but they nearly all possess a rather leathery type of leaf. 

 The individual species, however, vary considerably in this 

 respect. 



Epiphytes are not very abundant, and the undergrowth is 

 not luxuriant. The great number of lianes, however, make it 

 somewhat difficult to penetrate through the bush. Owing to 

 the activities of the white ant the bush is generally remark- 

 ably free from dead and decaying tree trunks. 



Though the bush as a whole is evergreen, yet there is a 

 slight tendency towards becoming deciduous. Calodendron 

 capense and Celtis kraussiana are both deciduous, and 

 Combretum kraussii and Grewia occidentalis are 

 almost so. Frosts are rare inside the bush, and the tempera- 

 ture of the soil never falls very low. The bush has, there- 

 fore, to withstand a dry winter, but not at the same time a 

 very cold one. Consequently it remains evergreen, but 

 it shows an approach to the deciduous woods of temperate 

 regions. 



3. THE THORN VELD FORMATION. 



The grasses of the thorn veld are the same as those of the 

 low veld. A great part of what is now treeless low veld 



