( 765 ) 



by its follen leaves on the ground, and sometimes by its characteristic 

 winged fruits; the leaves are noticeable on account of the colour 

 of their lower surface, which i-emains greyish wiiite for a fairly long 

 time. This greyish white or bluish grey colour is also rather striking 

 in the living plant. In the llowering period this giant of the 

 forest further attracts attention by its almost leafless condition in 

 tlie midst of evergreen trees. In alpine regions, at 2000 m. above 

 sealevel, in Western and Central-Java, (e.g. Preanger, Bagelen), this 

 species stands out by its dimensions, which are rather considerable 

 for a high altitude; so, for instance, at 2200 m. sealevel, on the 

 G. Kcmbang near Bëdaka, a specimen was 20 m. high, with a 

 trunk 4 »T- hi diam. The above data about Java, relating to oecological 

 conditions and geographical distrubntion, have been taken fron» 

 observations, made by me in Java 1888 — 1903, and mostly published 

 in KooRDERs and Valeton I.e. 257 — 258. — In the National Herbaria 

 at Leiden and at Utrecht I found with the specimens, collected in 

 Java by Jingiiuhn, Blumk, Reinwardt, etc., and now examined by 

 me, no special data about oecological conditions: in most cases there 

 was only written on the labels "Java" without further indications. 



§^ 2. Means of dissemination. 



The only means of dissemination is the fruit, known as samara, 

 which is primarily intended for distribution by wind, but which 

 seems, in addition, to have a certain capacity for being transported 

 by water, according to an experiment of mine. At least, if the 

 fruits are quite dry, they remain floating for some days on a 3^ 7o 

 solution of common salt. In this species the fruits are produced in 

 Java, as far as is known, only once' a year, but tlien mostly in 

 great numbers. Although the winged fruits are fairly heavy (when 

 dry they weigh about 100 milligrams, the wings, which are often 

 5 cm. long and 2 cm. broad, being included), and although I never 

 found in Java any indication, that tlie fruits are distributed by 

 animals, distribution must nevertheless take place easily, as is proved 

 by the large number of localities, cited above, where the tree is 

 found. As the occurrence of the species is limited to the higher 

 regions of several active volcanoes, at places which are more than 

 40 kilometres apart, and which are separated by hot plains, in which 

 the species has ne\er been found wild in Java at the present time, 

 it would appear, that the force of the wind on the higher mountains 

 of Java is sufiicient for transport over a distance of 40 kilometres, 

 even of such large samarae as those of Acer niveum. 



52 

 Proceedings Royal Acad, Amsterdam. Vol. X, 



