119 
groves chiefly consisting of various species of Ficus, of Pipturus 
meanus Wedd., Macaranga Tanarius L. and other trees and 
shrubs. These clusters of trees become more and more numerous, 
would seem to coalesce, and with time will occupy the greater 
part of the steppe. At present the foto still shows them isolated 
(see Plate XIX, fig. 2). Here and there this grassy plain advances 
as far as the littoral zone. This is succeeded by the young 
virgin forest of the ravines, stretching as far as the top. In 
some parts there are still dry ridges set with ferns and glagah, 
and at the summit one comes upon the last remains of the 
fern-zone, mingled with glagah and stunted trees from the 
ravine-flora. This covers, and will propably continue to clothe 
for some time to come, the summit proper as well as the very 
highest ridges. Continued research will be needed to define all 
this more completely. Tbe most remarkable thing, as I have 
mentioned before, is that especially in the higher ravines the 
forest is formed by practically one plant, which in Java and 
Sumatra is a small forest-plant under tall trees, viz. Cyrtandra 
sulcata Bl. But this plant also, it is to be supposed, will after 
a lapse of time have to be content with a more modest place 
then is now the case. 
When we apply ourselves to a consideration of the problems 
that loom largest in studying the causes by which it was made 
possible for these totally devastated islands to be furnislied 
again with a new vegetation in a comparatively small number 
of years, we shall conclude that there are mainly two. The 
first question is: In what manner did the plants get there? the 
second: In what way was the soil ‘made suitable to yield a_ 
sufficiency of food to the plants? And on further refiection the 
second question would appear to be still more important than 
2 the first. It is indeed to be regretted that in this field die . 
researches have been very inadequate, and now it is of course” 
too late: for a long time the ground has ceased being sterile, 
as it was shortly after the eruption. If Krakatau had been a 
mass of rock difficult to disintegrate by atmospheric influences, = 
2 the vegetation would have been still insignificant ; ‘but the ae a 
. te matter will eed weather = secoelly ele 
