

3H. Ill 



LOCALITY 51 



:he time of the highest flood and begins pushing its 

 adicle through the spongy pericarp. When the fruit 

 has dropped into the water its centre of gravity is so 

 contrived that the radicle lies underneath, and when 

 :he pericarp gets water-logged and the fruit sinks to 

 :he oozy bottom, the root can, at once, proceed to 

 make itself firm in the soil. With this as well as with 

 tnost water-borne fruits a sluggish current is necessary 

 or proper regeneration and for dispersion of the seed, 

 a-nd too great a clearing of trees may at once stimulate 

 a current which will bear the fruit away. An allied 

 Dree of the above (V. obscura) will be found in the 

 tracts liable to inundation on the eastern side of the 

 [island. In the river swamps of Burma the forest will 

 Ibe a mixed one of evergreens and leaf-shedders, such as 

 lAnogeissus acuminata, Mangifera longipes, Xantho- 

 vhyllum glaucum, with several species of Eugenia, 

 Elaeocarpus, Symplocos, also Cassia Fistula. 1 Here, 

 in order to resist excessive transpiration, the leaf-shedders 

 are said to be leafless during the rainy season. 2 In 

 places, inundated lands may degenerate into savannah- 

 forests or savannahs, and they may be only grassland. 

 But the last-named condition is largely due to the fires 

 which, in the dry season, sweep over these plains. The 

 wamps of the Upper Nile, generally known as the 

 Sudd region, are an example of this, for I have found 

 a number of trees such as Crataeva Roxburghii, Tri- 

 chilia emetica, Kigelia aethiopica, Acacia Suma, 

 Euphorbia Candelabrum, Borassus Jlabellifer, etc., 

 [trying to gain a precarious footing in these swamps, 

 | together with the curious pith-tree or Ambatch (Her- 

 miniera Elaphroxylon), which, however, was more 

 constantly under water. Several of the trees and 

 shrubs were found to grow on the summits of termite 

 nests. 



In tropical South America the tree which is at 

 present of the greatest economic importance, the Para 

 Rubber (Hevea braziliensis), is to be found in situations 



1 B. Ribbentrop, op. cit. p. 30. 2 Schimper, op. cit. p. 385. 



