392 



ZONES AND REGIONS 



[Pt. Ill, Sect. I 



bound together by a confused mass of delicate climbing plants. Should 

 the trees be less dense, the spaces between them are occupied by stubby 

 underwood in which young trees struggle for space with true shrubs and 

 small Pandani, or Crinum asiaticum forms thickets five or six feet high 

 between the tree-trunks. 



' The leaves of these plants are frequently quite large, but nevertheless 

 they exhibit in their structure the effects of unfavourable conditions in 

 reference to transpiration, especially in the outer fringe of the formation, 

 where the soil is richest in salts. The foliage of the larger trees is either 

 very dense, or, as with so many denizens of dry districts, is disposed 

 umbrella-like or in tiers ; the leaves are thick and leathery (Calophyllum 



Fig. 2 13. Littoral formations. In the background, littoral forest of Barringtonia-formation. In 

 the lagoon, young Rhizophora. Java. From a photograph by Warburg. 



Inophyllum, Terminalia Catappa, Barringtonia speciosa), or succulent and 

 juicy (Scaevola Koenigii, Pemphis acidula, Morinda citrifolia, Clerodendron 

 inerme, Tournefortia argentea, Ximenia americana), frequently in their 

 younger parts densely hairy (Pemphis acidula, Sophora tomentosa, Tourne- 

 fortia, Thespesia populnea, Heritiera littoralis), rarely provided with a coat- 

 ing of varnish (Dodonaea viscosa). Casuarina equisetifolia reminds one, on 

 a larger scale, of the species of Tamarix in the Mediterranean region ; the 

 finely pinnate species of Albizzia and Acacia, the bulbous plants, the 

 narrow and hard -leaved grass, recall dry savannah and steppe. 



' As the distance from the sea increases, the protective measures against 

 transpiration become less pronounced ; the thick, juicy leaves of Clero- 



