159 
the single excursion to Sebesy yielded 359 species, whilst on 
the many Krakatau expeditions 259 were collected. But it should 
be borne in mind that on Krakatau man has played a very 
modest part as a transmitter and a mach more important one 
on Sebesy. On Sebesy grow a good many cultivated plants and 
a number of typical agricultural weeds, which may of course 
have been conveyed thither by other intermediaries than man, 
but may on the other hand quite as well have come along 
together with the cnltivated plants. There are no certain 
means of determining this. In the first list the plants that 
are now cultivated will be found marked with (cult.) behind 
the name. 
On comparing the plant-associations of Krakatau and those 
of Sebesy the following remarks may be made: 
1°. As to the littoral vegetation: nearly all these plants belong 
to the typical beach-plants. On Krakatau but especially on 
Verlaten-Eiland this vegetation covers a very large area and is 
accordingly very rich in species and in individuals. On Sebesy 
this vegetation is restricted to narrow belts in front of the coco 
forest and the coast wall, and to the Northpoint of the penin- 
sula Pulu Pandjang, where a fairly broad sandy beach without 
an abruptly rising coast-wall has been formed. The Ischaemum 
muticum L. which trails along the beach itself with long inter- 
nodes, has developed at Verlaten Eiland into a kind of meadow 
of knee-high plants standing close together, the like of which 
is not found on Sebesy. 
On Huismans-Eiland I found on coral rocks sticking out of 
the water a number of robust specimens of Cordia subcordata Lmk., 
a plant which grows in similar spots for preference. 
2°. the Barringtonia formation: both on Krakatau and on 
Sebesy it is confined to very narrow belts behind the first zone 
of plants; on Verlaten-Eiland alone a few places are found 
where this formation is deeper. 
3°. the Casuarina-formation; on Sebesy this is limited to a 
narrow zone on the sandy peninsula, Pulu Pandjang. On Kra- 
katau it is found in several places mostly already fairly old 
with few rejuvenated parts. Little forests are found dotted about 
