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probably soon regenerated from its remnants, but many years had 

 to pass before these young trees could produce so many fruits that 

 a rich forest-vegetation all over the island could arise. Possibly 

 lack of fruit-dispersing animals has also played a part but this can 

 no more be examined now. The fields of pumice and ashes near 

 Zwarte Hoek that were investigated by Penzig are situated in such 

 a locality that seeds from the higher ravines on the south-east- and 

 east-side of the island cannot at all be carried there by rainwater 

 and hardly by wind. A too scanty import of seeds therefore can 

 be the main cause of the lack of forest in localities fit for it. 



It is quite well possible that in 1897 the higher part of the 

 ravines on the south-south-east and east-side of Krakatao bore 

 already young forest. One should remember that Treub in 1886 

 from the sea, hence at a great distance, saw already plants near 

 the top of the mountain, and that therefore these plants must have 

 been rather large. It is quite possible that they were shrubs or trees. 



As to the mode of import, it is next to certain that the whole 

 of the littoral vegetation was new and had been mainly or exclusively 

 introduced by the sea. It is utterly unknown from where the plants 

 found in the interior came, nor how they were imported and in 

 which numbers. 



If we now proceed to state the reliable results given by 

 P e n z i g's trip we can formulate them as follows: 



1. The littoral vegetation at Zwarte Hoek was in 1897 much richer 



and denser than in 1886. The oldest parts of the beach (that 

 were at best 14 years old) had in 1897 already been leached 

 out and bore locally a rich growth of the halophobous Saccha- 

 rum spontaneum. The copious rain-fall and the situation of the 

 beach at the base of a high steep wall are the cause of that 

 leaching-out having taken place so rapidly. 



2. As might be expected, the kremnophytic vegetation of the 



steep walls of the interior has remained practically the same 

 between 1886 and 1897. 



3. The vegetation of the investigated parts of the interior had grown 



much denser and had in 1897 much the same aspect as young 

 secondary vegetations in Java in rather moist climates. It con- 

 sisted mainly of grasses and ferns with scattered Dicotyledons. 

 Those plants formed in the moister localities a tall and dense 

 vegetation, on the less moist ridges a thinner and less tall one. 



