63 
tively so short (as we have seen some galls were already there 
as early as 1896) is noteworthy enough and shows again that 
the ways of Nature in reaching her object are manifold. Her 
means are infinite, time and the number of possibilities are 
indeterminate. | 
It is not only in a horizontal direction that galls may spread, 
but in some cases in a vertical direction as well, and in this 
connection I would draw attention especially to the foremen- 
tioned gall of Eriophyes pauropus Nal. on varieties of Nephro- 
lepis. This plant occurs very abundantly on Mount Rakata 
(2500 ft high) from the foot to the very summit: the galls 
likewise are to be found practically all over it. 
Also the Psyllida-gall on Thespezia lampas is remarkable. This 
plant does not yet figure in the list of Krakatau-plants published 
by Eryst'). I did find it however in a table of plants found by 
Dr. Vaeron in 1904. I myself found only one single specimen 
of it on the shore of the islet called Verlaten-Eiland. It was 
however bristling with galls. 
Let us now however make an end of speculating on surmises 
and return to the facts. 
Most of the galls I found on genuine coastplants or on plants 
occurring within a short distance of the shore. There it was 
also that the vegetation comprised the greatest variety of spe- 
cies. On climbing the mountain-slopes the number of diffe- 
rent phanerogamous plants becomes gradually smaller, whilst 
contrarily the number of individuals belonging to the same 
species increases considerably. Several of these species a. 0. 
Cyrtandra suleata, (which forms the greater part of the vege- 
tation) not bearing any galls, the number of different gall-growths | 
becomes relatively smaller as one rises higher on the slopes. _ 
Only a few species occurred on or near the summit, viz. the 
mite-galls on Ficus jistulosa and those on Nephrolepis hirsutula; 
together with the i on Ficus ribes - Nauclea a 
purascens, 
te 4) AL ic Die neue Flora der Vulkan-insel Krakatau, Viasat, der cr a - 
- a ‘Heft 3. cae: ce 
