^Q THE FACTORS [Part I 



entirely disappeared. The ribbed fruits of Nipa fruticans also abound ; the wrinkled 

 fruits of a Canarium or merely their remnants in the form of stones ; the large 

 mitre-shaped fruits of Barringtonia speciosa, as well as the oblong ones of B. excelsa 

 and the much smaller fruits of a third species not determined ; the boat-shaped 

 stones of Terminalia Catappa (Fig. 34), often much worn by friction and with the 

 thick husk infested with several kinds of creatures, especially Cirripedes ; the 

 irregularly angled seeds of Carapa obovata looking as if they were cut out of bottle- 

 cork, their husks being also perforated or gnawed ; the large angular seeds of 

 Pangium edule; the globular stones of Calophyllum Inophyllum (Fig. 35) ; fruits 

 of various Pandani ; pods of Pongamia glabra and of Cynometra caulifolia ; the grey 

 irregularly rounded seeds of Caesalpinia Bonducella, the flat dark ones of a Dioclea, 

 the oblong ones of a species of Erythrina ; the seedlings of a Bruguiera. By care 

 fully searching, a number of smaller fruits and seeds may be found, such as the 

 stones of Lumnitzera racemosa or L. coccinea, those of Scyphiphora, and the seeds 

 of Ipomoea Pes-caprae. 



' In most cases, even when the fruits are much attrited, the seeds are quite sound, 

 and germination has apparently already commenced in some of them ; in this 

 respect there is a striking difference between different species which is probably 

 due to the various degrees of durability of the germinating power. Of coconut 

 palms, oaks or Canarium, there are no young plants, and the seedlings of Heritiera 

 are few in comparison with the vast number of its drifted fruits. Somewhat more 

 numerous are the seedlings of Barringtonia speciosa and another species of the 

 same genus, much more so than of Calophyllum Inophj'llum, Cerbera OdoUam, 

 and Carapa, and commonest of all are those of Ipomoea Pes-caprae and of various 

 Leguminosae. Seedlings of species, the ungerminated seeds of which I did not 

 discover, are very numerous, especially those of Ricinus communis and of several 

 other Euphorbiaceae.' 



The littoral flora includes an extraordinarily high percentage of wide- 

 spread species, which are often cosmopolitan within their climatic zones, 

 and which owe their extensive area of distribution to marine currents, 

 as is proved by the presence of their seedlings on heaps of drift and by 

 investigations into the floating capacity and germinating power of drift- 

 seeds. 



Investigations which I carried out as to the duration of the floating capacity of the 

 seeds of various Malayan littoral plants in water containing 3J % of salt had to be 

 interrupted before all the seeds had sunk. Seeds of Suriana maritima floated for 

 143 days, those of Hibiscus tiliaceus for 121 days. Other seeds or indehiscent 

 fruits floated from 10 to 70 days and then sank. Investigations by Guppy at 

 Buitenzorg, which had also to be stopped after 53 days, proved that the germinating 

 power of a considerable number of seeds was unimpaired after 40-53 days. 



The dispersal of littoral plants by marine currents has been of consider- 

 able importance in establishing plants on islands and coasts not merely in 

 the past but at the present day, as Treub was able definitely to provel 



