6. On April 26th Dr. Docters van Leeuwen attempted once more to ascend 

 the top, this time in the company of Mr. H a n d I |r., a native plant-collector 

 and two coolies. The ascent was difficult, not only because of the steep acclivities 

 and the loose quality of tlie soil, but also because of the moist heat prevailing 

 in the densely grown ravines. Water was nowhere to be had. Such steep accli- 

 vities, sometimes amounting to more than 30%, are usually found only in the 

 higher mountains where the cooler climate renders the ascent less exhausting; 

 on Krakatao the steeps began at slight elevations above the sea. Everytime 

 the end of a ravine was reached, whereupon the investigators had to scramble 

 up obliguely against the crumbling wall to strike another gorge reaching a little 

 higher upwards. At eleven o'clock they were still in the forest but a change 

 in its composition was already perceptible. The same trees still recurred as 

 those beneath, but some species became more prevalent, like Villebrunea 

 rubescens KI. and Ficus ribes Keinw., which also in |ava belong more properly 

 to the mountainous regions. I he most remarkable thing was that, as the ex- 

 plorers rose higher, the forest was almost wholly constituted of Cyrtandra 

 sulcata KI- The plants stood side by side in thousands, each consisting of a 

 number of strong branches proceeding from a common centre and reaching a 

 height of 3 4 m. At a height of + 600 m. between the Cyrtandras, on which 

 a host of epiphytes had fastened, typical mountain-trees were growing, i.a. 

 Ficus rihex Reinw. I he whole forest began to wear a moister aspect; from the 

 branches depended heavy festoons of a kind of scale-moss 1 ), that were full of 

 water. At last the explorers reached a point where a huge specimen of Ficus 

 rt'tusa L. '-') rose high above the monotonous vegetation (chiefly composed of 

 Cyrtandra sulcata KI. ), that seemed to cover all the upper half of the mountain. 

 With its thousands of aerial roots") this tree covered a large area. 1 he humidity 

 increased, the ground got wetter and more slippery, but between the ravines 

 were dry, often narrow ridges, sometimes interrupted by cross-grooves, and 

 consisting of granular matter sliding away underfoot and held together by 

 Saccharum spontaneum L., Imperata cylindrica P. B. (= I. arundinacea Cyr.), 

 but especially by the ferns Nephrolep/s exaltata Schott ( N. hirsutula Presl) 

 and Dryopterin unita O. K. (= Dr. cucullata Christ.). At half past twelve the 

 verge of the rupture just below the top was reached. The trees began to 

 look stunted and in some places there were already patches of Saccharum 

 spontaneum but Cyrtandra sulcata still dominated, rather smaller indeed but 

 otherwise apparently very little the worse for the fierce light. At half past 

 one the explorers reached the top, which was entirely covered with Saccha- 

 rum spontaneum L. and with 2 very tall species of ferns, Nephrolepis exaltata 

 Schott and Dryopteris unita O. K. over which crept Trichosporum voluhile 

 Nees. Cyrtandra sulcata HI. was still present, likewise Ficus ribes Reinw- and 

 F. fistulosa Keinw. I he grass reached above-head The whole ascent had 



*) The English text has seale-rnoss, which apparently is a misprint for scale-moss, 

 i.a. a representative of the order Hepaticae (Dutch: levermos). The Dutch text however 

 has loofmos, i.e. a representative of the order Musci Frondosi. Probably the reading of 

 the Dutch text is right: at least Max Fleischer [Beit rag zur Laubmonsflora der 

 Vulkaninsel Krakatau in Ann. |ard. Bot. Buitenzorg, XXXIII (1923), p. 107] mentions 

 as a species found on this trip by Mr. Docters van Leeuwen Floribundaria 

 f/oribunda F/eisch. as ,,in feuchten Schluchten, von den Aesten und Stammen herab- 

 ,,hangend 26/4/ 19. Bildet anscheinend Massen-vegetation wie in den feuchten Berg- 

 ,,waldern der javanischen Vulkcingebirge". Everyone who has visited the West-lavan 

 rain-forests has remarked the dense festoons of Aerobryum, Aerobryopsis or Flori- 

 bundaria, pending from the trees. See also | U n g h U h n, lava, 2nd Dutch Edition I, 525; 

 German Edition I, 382. 



-) As appears from Appendix III to the Dutch text this tree was growing at an 

 altitude of 700 m. 



') The English text has here aerial shoots. From a comparison with the Dutch 

 text it appears that aerial roots are meant. 



