117 
of seeds they could multiply without hindrance when the place 
was suitable to their growth. Backer thought he could distin- 
guish three zones: the littoral-belt, consisting of the beach- 
plants proper and Barringtonia-formation; next a region of 
mixed forest, separated from: the interior by a broad tract of 
impenetrable jungle-grass. The third zone is that of the moist 
ravines in which occur a few species of trees, a.o. varities of 
Ficus, epiphytes however being very rare. Also the number of 
ferns found by Mr. Backer does not far exceed those of former 
explorers. The fern-zone found by Trevs, which appeared to 
cover the whole of the interior, is either crowded out to higher 
regions or else has vasished. Mr. Demment, photographer to the 
topographical-survey-brigade, who attained the summit of Mount 
Rakata after Mr. Backrr’s visit, stated that near the top the 
trees has entirely ceased, yielding place to ferns varied by 
shrubs and glagah. 
Eleven years ago the results of the exploration therefore 
were that there were three zones (properly five), that the fern- 
zone was pushed back entirely to the top and that the number 
of epiphytes was very small; in the list of Ernsr only one is 
mentioned, viz. the fern Drynaria quercifolia J. Sm. 
On comparing the plants now found by myself, much appears 
to have been altered, even after making due allowance for the 
fact that this time the summit was reached. For also in the 
lower ravines a great many more plants occurred than formerly. 
My own list (which may be found in the appendix 1) and in 
which the previous finds have also been inserted, now numbers 
no less than 272 plants, against 137 in the list of Ernst. 
When we inquire in which groups of plants the increase took 
place, we arrive at the following results: The beach-plants have 
not greatly increased. Of genuine littoral-plants only seven new © 
ones have made their appearance. And let it be remembered 
that this belt of the flora is of course the best explored, be- | 
cause one is each time obliged to traverse it when one wishes 
to reach the other zones. Contrarily the number of forest-plants ~ ee 
has been very greatly added to. I found 68 species in all, whereas oo 
ee 
ing ; those found ae Mr, Backz. ae 
