225 



found 16 forms. Genuine fungi appear in Ernst's list to the number of 3; 

 Mr. Docters van Leeuwen found 33 of them. Most noteworthy is the 

 great increase of epiphytes; many of them demanding other surroundings than 

 other plants Many species desire a constantly moist atmosphere and therefore 

 thrive most luxuriantly in the humid wild forests of the mountains. At about 

 600 m. 1 ) Trichomanes humile was found, whose leaves are very unfit to 

 resist a long desiccation. A great change in the conditions of life must 

 have come about and this was that the few forest-plants which were to be 

 found in the ravines during Backer's visit have multiplied astonishingly 

 since 1908, covering the ravines with a dense forest, consisting of few species 

 but of an incredible number of individuals of each. In 1919 they already formed 

 deep shadows and shed leaves plentifully, the ground was covered with a 

 rather thick -) layer of leaf-mould, and with the humus arises the possibility 

 of the development of numerous forest-plants. Moreover the mountain-peak is 

 frequently wrapped in clouds, consequently very moist (as Mr. Docters 

 van Leeuwen had occasion to be aware when climbing it) and also so a 

 good habitat for epiphytes. 



Mr. Docters van Leeuwen is wrong in saying that during 

 my visit in 1908 but few forest-plants occurred in the ravines. The 

 lower parts of the ,,waldartige Bestande" observed there as early as 

 1906 by Ernst and his companions were reached in 1908, and in 

 my short paper on the expedition of that year (See Chapter IX) I 

 expressly stated that, though the number of species found was small, 

 the number of individuals belonging to them was often enormous. 

 As a matter of fact, many of the ravines investigated in 1908 at an 

 altitude of 200 400 m. were densely wooded; as we came higher 

 up the mountain the trees (of the same species) became larger, 

 from which may be inferred that the woods had extended from 

 above downwards. Most probably this process has continued ever 

 since 1908; in 1919 the forests may have approached considerably 

 nearer to the coast than in 1908. The woods between 200 and 

 400 m., still comparatively young in 1908, were in 1919 eleven 

 years older, the trees were higher, their crowns bigger and denser, 

 consequently the forest darker, more humid, better fit for epiphytes; 

 the undergrowth may have become richer in species. This is the 

 ordinary course of events with young secondary forests in rainy 

 climates in Java (See p. 209). Cyrtandra su/cata BI. which in 1908 

 was not seen 3 ) beneath an altitude of 250 m. was now already 

 collected at 50 m. Hence Mr. Docters van Leeuwen may 

 be right in saying that in the lower ravines much more plants 

 occurred than formerly, though this is not proven and, moreover, 



1 ) According to the Dutch text. The English text gives 1800 feet or + 540 m. 

 -) This is the correct translation of the Dutch text: vrij dik, which is somewhat 

 vaguely rendered in the English text by: ,,of some thickness". 

 ! ) This is not the same as did not occur. 



