no 



have reached a greater height than 200 a 300 m., it is even pro- 

 bable that they have remained below that. Consequently they explored 

 only a very small part of Krakatao, the beach and the lower slopes 

 on the north-western side, and the investigation was but a very cursory 

 one. Which was the vegetation of the other parts of the is/and in 

 1897 is fully unknown. This must be taken into account when judging 

 of the results of this trip. 



The rocks and the pumice- and ash-fields explored by T r e u b 

 and Penzig in 1886 and 1897 seem never afterwards to have 

 been visited by a botanist, at least none of the subsequent authors 

 on Krakatao has mede any communication about the vegetation on 

 these slopes '). The investigations here came to an end with the 

 excursion of Penzig. It is quite unknown whether since 1897 the 

 aspect of the flora has been modified and if so in which manner. I 

 myself think it probable that the basaltic rocks will continue to bear 

 a thin vegetation of kremnophytes for yet many years to come. But 

 I do not think an investigation there to be urgent: now that the 

 starting-point of all investigations viz. it being out of doubt that 

 the vegetation was totally destroyed in 1883 has disappeared, 

 the kremnophytic vegetation on Krakatao cannot be considered to 

 be more important than any other one and many of these kremno- 

 phytic vegetations may be reached and investigated much more 

 easily and at much less cost. 



After having left Krakatao Penzig and his companions paid a 

 visit to Verlaten Eiland where they spent three hours in exploring 

 the beach on the eastern side. From there they went to Lang Eiland, 

 then since a short time inhabited by some officials of the Topo- 

 graphical Survey Service, where they in haste collected plants on 

 the beach till it grew too dark. On the results of the trips to Ver- 

 laten Eiland and Lang Eiland I shall be silent; they are of no importance 

 for the revegetation-problem of Krakatao. 



Before mentioning the conclusions drawn by Penzig from 

 his exploration I give a corrected list of all plants found by 

 him on Krakatao, as far as possible with data about habitat and 

 frequency. None of Penzig's plants is present in the Buitenzorg 

 Herbarium, but there are some collected by Boerlage on this 

 same trip. 



^Valeton (Cf. Chapter VII) tried in 1905 to climb them but had the 

 misfortune to luxate an arm, by which accident he was compelled to give up the 

 ascent. 



