vn] PLANT POPULATION 113 



late Dr Treub, who visited Krakatau in 1886, con- 

 cluded that the first colonists were blue-green Algae 

 associated with Diatoms and Bacteria. These formed 

 a suitable nidus for the spores of Mosses and Ferns, 

 and for the seeds of some Flowering plants adapted 

 for dispersal by winds. On the beach were found the 

 fruits and seeds of Flowering plants some of which 

 had germinated ; many of them belonged to the 

 characteristic strand-flora of the Malay Region. But 

 plants introduced by animals or by man were not 

 found by him on this visit, which took place only 

 three years after the eruption. In 1897 Penzig 

 visited the island, and estimated that of the Flower- 

 ing plants noted 60*39 / had reached it by ocean 

 currents, 32'07 % by wind agency, and only 7*54 % had 

 been transported by fruit-eating animals and man. On 

 a subsequent visit by a party of botanists in 1906, the 

 results as stated by Ernst show that though these 

 proportions for Flowering plants were not exactly 

 maintained, still the largest number were borne by 

 water transit, and the smallest by animal agency. If 

 the Ferns be added to the list of plants with wind- 

 borne germs, this would raise the estimate of the 

 Vascular plants which had arrived in this way to 37/o- 

 Thus for an oceanic island the most effective agency 

 of transit is water : wind-carriage takes a middle 

 place, and transit by animal agency is the least 

 effective of the three. 



B. 8 



