19 



Point nest besoin de discuter la possibi/ite que les plantes nouvel- 

 lement instal/ees a Krakatau y soient amenees par /' intermedia/re de 

 Fhomme. L'lle est inhabitee, inhabitable et difficile a visiter. 



Enfin la composition elle-meme de la //ore actuelle de Krakatau, 

 demontre une fois de plus qu elle n'a pu tirer son origine ni de la 

 {lore anterieure ni par I' intervention de /' homme" '. 



In order to rightly value the conclusive force of this reasoning 

 we have to examine its bases. T r e u b advanced two arguments for 

 his belief in the total destruction of the flora. The first holds that the 

 destruction was the inevitable consequence of the island being covered 

 by a dense and thick layer of glowing eruptive products; the second 

 deduces the destruction of the old vegetation from the composition 

 of the new one in 1886 Both of these arguments will here be 

 examined. 



Has it indeed irrefutably been proven that in 1883 the entire sur- 

 face of Krakatao was covered with a layer of ashes and pumice '), 

 thick and hot enough to destroy all vegetable life ? This has so 

 universally been taken for granted during more than forty years that 

 the time has come to consider whether the belief is in harmony 

 with the facts. In the first place we have to examine whether T r e u b 

 carried out his investigations on a scale, large enough that his con- 

 clusions may be considered to be valid for the entire island. I refer 

 here to what I have said in the first chapter (p. 5) about size and 

 nature of Krakatao. 



It is strange that T r e u b himself did not mention which part of 

 the island was investigated by him. In order to get information 

 on this point I have applied to the renowned Krakatao-specialist 

 Verbeek (whom I quoted already before as I will do many times 

 more) in whose company T r e u b made his excursion. From letters of 

 Verbeek it appears -') that T r e u b did not reach the higher 

 parts of the island but restricted his investigations to the lower 

 localities on the northwestern side near Zwarte Hoek. Verbeek 

 assures that at this time no other plants were growing there than 

 these mentioned by T r e u b ;i ). 



J ) Many authors, i.a Schimper (Pflanzengeographie (1908) p. 90), Penzig(Ann. 

 lard. Bot. Buitenzorg XVIII (1902) p. 103) and Warming (Pflanzengeographie, 3te Aufl- 

 (1918) p. 688) wrongly think that in 1883 Krakatao was covered by lava also. But during 

 the eruption of that year no lava has flown out (Cf. also Ernst- Neue Flora Vulkan- 

 insel Krakatau (1907) p. 4). The present lava-streams are part of the old mantle of 

 the volcano. 



2 ) Letters of April 25th 1922 and May 7th 1923. 



3 ) In Ann. )ard. Bot. Buitenzorg. Ime Serie VII (1888) p. 213 seq. 



