271 



giving a rather inaccurate list of all plants found til! 1919 on the 3 

 islands of the Krakatao group, where he has added to the name of 

 each plant its means of distribution which, as appears from 17 here- 

 before, is considered by him also as the means of introduction. His 

 assertions in this matter are not based on actual observation but, as 

 I have already pointed out in the introductive chapter, he was, like 

 former authors on the subject, only guided by the quite unwarranted 

 opinion that Cryptogams and such Phanerogams as possess light or 

 winged seeds were carried over by wind, plants with fleshy, succulent 

 or adhering fruits by birds or bats, the rest by the sea. Sometimes, 

 without giving however any reason for his opinion, he adscribes 

 introduction to man. It needs scarcely saying that guess-work like 

 this is entirely devoid of value and cannot be seriously discussed. 

 I can only state that nobody knows which plants of the interior have 

 been introduced into Krakatao after the eruption and that nothing 

 at all is known of the mode of introduction. 



Appendix IV to the Dutch text of the paper of Mr. Docters 

 van Leeuwen contains a list of galls found on Krakatao. As this 

 Appendix is not found in the English text and the subject is more 

 extensively treated by the same author in another paper '), I shall 

 revert to it in my discussion of that publication (Chapter XII). 

 Appendix V to the Dutch text, likewise omitted in the English text, 

 gives a list af all birds seen by Mr. Bart els on Krakatao and 

 Verlaten Eiland from April 24 -29th 1919. For the study of the 

 revegetation of the island it has at present no importance. 



If we now proceed to sum up the real results of the trips of 

 1919 we can only state that in the years elapsed since 1908 no 

 new elements were found to have appeared in the littoral flora. The 

 secondary forest of the interior had probably - as might be expect- 

 ed beforehand extended considerably downwards. The lower parts 

 of it had presumably become denser, richer in trees and in under- 

 growth. Whether these additions had come over from such parts of 

 the forest as were not examined before 1919 or whether they had 

 been introduced since 1908 from outside the island is absolutely 

 unknown. Rather many epiphytes were found, a phenomenon of 

 common occurrence in old secondary forests in wet climates. These 

 epiphytes, mostly ferns and orchids, may have been introduced after 

 the eruption, the epiphytic plants in all likelihood having been quite 



l ) Mr. W. Docters van Leeuwen, The Calls of Krakatao and Verlaten 

 Eiland in 1919, in Ann. |ard Bot. Buitenzorg XXXI (1920), p. 57 seq. 



