THE GALLS OF ,,KRAKATAU” AND ,,VERLATEN 
EILAND” (DESERT ISLAND) IN 1919 
BY 
W. DOCTERS VAN LEEUWEN. 
INTRODUCTION. 
Among the naturalists who have visited Krakatau before me, 
there has not been any one who has directed his attention to 
the galls to be met with there. This is after all no matter, for it 
is not everybody who can make a success of gall-hunting in a 
tropical flora. It is a thing to be acquired with time and prac- 
tice. Moreover the galls most prevalent in these parts are not 
conspicuous by peculiarities of shape or striking hues. Still it 
is to be regretted that it has not been paid attention to, 
for now, 36 years after the eruption, the number of gall-varieties 
is fairly large and the manner of their arrival on the islands 
is now comparatively little known. As far as possible I exa- 
mined the specimens of the plants found there by Taxus, Va- 
Leron, Backer and others, now reposing in the herbarium of te Go- 
vernment Botanical Gardens. But as was to be expected, there 
were but few galls on these, which however is no proof that 
they may not have been there before my visit to the islands. 
Of two plants it is certain that they bore galls on these 
islands long ago. Among the specimens of Nephrolepis hirsutula 
Pr. collected by Borrtace on ,Lang-Eiland”, Nov. 29th 1896, 
there were a couple of leaves [bearing some of the generally 
ee prevalent mite-galls caused by Eriophyes pauropus Nal. 
What makes it probable that this gall was already then pre- : 
: sent also on Krakatau and Verlaten-Eiland, is that it is among ae 
the most occurring there now. Also of a ineanus — hay 
3 ‘Ann. Jard. Bot, Buitens. Vol. XXXI-- - hae or 
