248 



Summarizing, from the paper of Mr. Docters van Leeuwen 

 we do not learn whether the littoral vegetation in 1919 differed from 

 that of 1906 or 1908. Much less has it been proven that this vege- 

 tation had grown richer in species in the 11 or 13 intervening years. 

 The investigation of the littoral flora which presents no serious 

 difficulties but requires much care, was carried out in April 1919 

 so very negligently that half a year afterwards no less than seven 

 species, all of them large perennials, were collected that had not 

 been found in April, though at least 5 of them were already present 

 in 1906 or 1908. There is no reason to believe that these species 

 had died out in April and had reestablished themselves again in 

 October. Even a big (male) specimen of the very conspicuous 

 Cycas rumphii Miq. with a trunk of almost one meter high was over- 

 looked on the beach of Zwarte Hoek (Cf. 7). Of many of the 

 plants found near the shore for the first time in 1919 we do not 

 know on which side of the island they occurred. The researches 

 on the coastal flora of 1919 have given us nothing reliable to 

 build upon, they have in no way advanced our knowledge of the 

 development of the flora. 



In Appendix 111 to his paper Mr. Docters van Leeuwen has 

 recorded 68 species under the head: ,,Forest-plants found by me on 

 Krakatau". Herebeneath these species have been arranged in accor- 

 dance with the systems of Christensen (Ferns) and Engler 

 and Prantl. Of each species not yet formerly found on Krakatao I 

 have given a few data on its distribution over Java and its means of 

 reproduction. Of none of the species Mr. Docters van Leeuwen 

 has mentioned the frequency; of many the habitat and the vertical 

 range are not given, the height mentioned apparently being often 

 only that of the locality where a specimen was collected. This 

 appears i.a. from No. 44 of the list, Ficus fistu/osa Reinw., of which 

 in 5 herebefore is said that it was frequent in the lower ravines, 

 whilst in Appendix III it is only given for the ,,summit of Mount 

 Rakata". In 5 it is said that Villebrunea rubescens was seen in the 

 valleys beneath an altitude d ) of 100 m. (at which point ,,the way 

 ,,was blocked by an absolutely unscalable precipice"), in Appendix III 

 the only height given is 200 m. Sometimes (No. 12, 35, 37, 46, 50, 58 

 of the list beneath) the English text it entirely silent as to the altitude 



1 ) In giving altitudes above sea-level 1 have everywhere followed the original 

 Dutch text. In the English text one meter, which is 3,28 English feet, has been wrong- 

 ly reckoned for 3 feet. 



