216 



plants, the occurrence of the hygrophilous Trichosporum volubile 

 Nees l ), the abundance of fungi, clearly prove that the east-monsoon 

 on Krakatao, as a rule, is repeatedly interrupted by rains. 



Mr. Docters van Leeuwen says that near the top he 

 found already patches of Saccharum, He might better have said that 

 he found still patches of this grass, which, together with //operate, 

 is on not too dry soils one of the first settlers in deforested localities. 

 Afterwards, at least when things take their natural course, these 

 two species are gradually superseded by young forest. We may 

 safely assume that 30 years ago Saccharum was more common in 

 the higher parts of Krakatao than in 1919, the year in which Mr. 

 Docters van Leeuwen made his trip. In a subsequent paper -) 

 the latter affirms that there were on Krakatao still large stretches 

 of Saccharum and Imperata, which ,,lent a peculiar aspect to the island". 

 Such large stretches of Imperata intermixed with Saccharum may 

 be met with everywhere in thinly populated deforested not too dry 

 localities in Java. From the description given of the vegetation in 

 1919 may be deduced that in the investigated parts the forest was 

 furthest developed and therefore probably oldest in the ravines at 

 an altitude of 600 700 m. This confirms my hypothesis (see pp. 26, 

 seq.) that in these ravines part of the old vegetation has survived 

 the catastrophe and that they have afterwards become starting- 

 points of a young vegetation. 



^ 7. On April 27tli Mr. Docters \<in Leeuwen and his companions embarked, 

 rounded tlie north side of tlic island and landed at Zwarte Hoek. 1 he steep 

 wall of the rupture was distinctly becoming green by grasses and some ferns 

 growing on it. On the beach at Zwarte Hoek were all sorts of littoral plants, 

 among which Spinifex littoreus Mcrr. Among the thick brushwood stood a 

 few young specimens of Cocos nucifers L. and also a well-developed specimen'^) 

 of Cycijs rumphii Miq. I his species is an exceedingly slow grower. Yet 

 the specimen found cannot date from before the eruption because this beach 

 did not yet exist then. In the excursion of the congress in Sept. 1919 a cf 

 specimen was found on the same spot. Ernst who explored the same locality 

 in 1906, did not mention the specimen found by Mr. Docters van 

 Leeuwen, which was ceitainly not older than 15 years. But Ernst speaks 

 of another specimen which Mr. Docters van Leeuwen was unable to 

 trace. I he visitors did not tarry long here because the cliffs bore only 

 a meagre vegetation. From Zwarte Hoek they went to Verlaten Eiland where 

 they stayed for 2 days. On April 29th they returned home. 



') This species seems to be rare in Java. Up to now it has only been found in a 

 few localities in wet places at comparatively low (30 ^00 m.) altitudes. See hereafter 

 the list of ,,forest plants" sub No. 64. 



'-) The Vegetation of the Island of Sebesy, situated in the Sunda-strait, near the 

 Islands of the Krakatau group; in the year 1921, Ann. [ard. Bot. Buitenzorg XXXII 

 (1923), 139. 



;! ) The Dutch text adds that this was a V specimen. 



