45 



during a season and decreases during the next so that plants that 

 have lived some time under favourable conditions afterwards perish, 

 their habitat being destroyed. Only on increasing or stable beaches 

 circumstances continuously favour germination, at least in the west- 

 monsoon, but even there many seedlings perish, the substratum being 

 often unfit for their further growth '). Along the sea-side of the 

 Barringtonia-formation one regularly finds seedlings of Nipa fruticans 

 Wurmb, and Avicennia marina Vierh. but these, without exception, 

 die early as they can only live in a constantly marshy or at least 

 very humid soil 2 ). The fruits of (jluta reng/ias L., a tree chiefly 

 occurring on riversides and in bog-forests in the plains, are frequently 

 washed ashore but young plants of some size are on the beach 

 found only in such localities where the ground-water is sweet and 

 the water-table high. Of Pangium edule Rein\v. one finds on the beach 

 often seeds but never seedlings - ! ) and the same is the case with 

 sundry species of Quercus. S c h i m p e r l ) mentions the same fact 

 for the seeds of Chydenanthus cxcelsa Miers. The fruits of Cerbera 

 manghas are very often found lying before or even on the beach- 

 wall; they may germinate there but soon afterwards perish. In 1921 

 K a m e r 1 i n g - r> ) quite rightly observed that on a beach where many 

 seeds or fruits of a given species are found, very often not a single 

 well-developed seedling grows except quite near an adult specimen 

 of the same species, the fruits or seeds of which therefore may 

 have been transferred over some slight distance only, but need not 

 at all have come over from far away. It is beyond doubt that, 

 except in well-sheltered localities as f.i. the increasing lee-side of 

 coral-islands in the Java-sea (l ), only an exceedingly small part of 



1 ) Cf. also S c h i m p e r, Indo-Malayische Strandflora (1891) p. 186 seq. The 

 coral-island Pulu Lang in the |ava-sea mentioned by him should not be confounded 

 with the volcanic island of the same name',) in the Sunda-straits. Sc him per (I.e. 

 p. 183) draws also attention to Lodoicea Seychellarum ,,cleren Fruchte bekanntlich 

 ganz reyelmassig an der Kiiste der Lakediven und sogar von Sumatra angeschwemmt 

 werden und dennoch die Palme nicht iiber die Seychellen hinaus verbreitet haben". 



2 ) On the sand- and pumice-beaches of Krakatao and Verlaten Eiland F. rust 

 and his companions found in 1906 many young seedlings of Nipa fruticQns \kurnib, 

 partly still living, partly already dead, but not a single older specimen (Cf. Ernst, 

 Neue Flora Vulkaninsel Krakatau (1907), p. 38). 



3 ) I his was already mentioned by |. Massart [Un botaniste en Malaisie p. 299 

 (151)]: ,,les rivieres les ont entratnees vers la mer, les flots les ont rejetees a la cote, 

 mais sans aucun profit pour I'espece car elles ont ete tuees par I'eau salee". 



4 ) S c h i m p e r, Indo-Malayische Strandflora (1W1 ), p. 173. 



5 ) Kamerling in Natuurk, Tijdschr. Ned.-lndie LXXXI (1921), p. 22. 



6 ) The vegetation of such parts of the beach of coral-islands as are exposed to 

 the surf often differs much from that of the sheltered parts. In the western half of 

 the Java-sea the south and sout-eastern sides of the coral islands bear as a rule, a 

 Pes-caprae or a Barringtonia formation, the north- and north-western sides a coral- 

 reef mangrove (Cf. pag. 38, footnote 1 ). 



") Pulu is the malayan word for island, Dutch: eilanil. 



