62 Means of Dispersal 



possible that the north-west monsoon may carry dust and small dust- 

 like seeds from the western part of the Archipelago to the peaks of 

 the eastern islands. In this connexion Beccari calls attention to the 

 long distances which volcanic ashes (eruption of Tamboro at Sum- 

 bawa in 1815) may be carried by currents in the upper regions of the 

 atmosphere; he also gives figures indicating the lightness of such 

 seeds as he considers may be distributed by wind. A seed of Nepen- 

 thes phyllamphora weighs 0'000035 grammes, seeds of Rhododendron 

 verticillatum and Dendrobium attenuatum 0*000028 gr. and 

 0*00000565 gr. respectively. As the north-west monsoon in the Malay 

 Archipelago has a high intensity it is easy to understand why Rhodo- 

 dendron, Nepenthes, and other plants peculiar to the mountains of 

 the western region and to the mountains of Java occur on the 

 mountain-summits of the Moluccas and New Guinea, and why, for 

 example, several Alpine Indian plants are met with on the Pangerango 

 (Gentiana quadrifaria BL, Ranunculus javanicus Reinw., Ranun- 

 culus diffusus D.C., Valeriana javanica BL, Primula imperialis 

 Jungh., Gnaphalium javanicwm Reinw., etc.). Beccari considers that 

 these have been carried by the north-west monsoon, to some extent 

 also by birds, from regions further west, first from Sumatra, and 

 thither from the mountains of India. He attributes very great 

 importance to the north-west monsoon, which is especially prevalent 

 from November to April, as a factor in the transport of seeds, more 

 particularly from the west part of the Archipelago to the eastern 

 islands. 



The observations of Junghuhn 1 on the conditions of the monsoon 

 wind in Java are not consistent with this conclusion. The west or 

 north-west monsoon, which produces cloudy weather in Java from 

 December to February, extends, according to Junghuhn, only a short 

 distance above sea-level, at most up to 1600 metres [5250 ft] on the 

 slopes of the mountains; while, on the other hand, the south-east 

 monsoon blows the whole year round in all parts of the atmosphere 

 at an altitude above 2000 metres [6600 ft.]. During the period of 

 twelve years during which he observed the direction in which the 

 steam-clouds of the volcano are drawn out as stripes in the atmo- 

 sphere reaching miles in length, he found that this is always towards 

 the west, W.N.W., sometimes W.S.W. and never towards the east, 

 not even when, in the months of January and February, a strong 

 westerly or W.N.W. wind brings the heaviest rain-showers over the 

 low alluvial flats. His remarks in another passage (loe. cit. p. 408) 

 diminish, to some extent, the force of these conclusions: he writes, 



1 Junghuhn, F. Java, seine Gestalt, Pfianzendecke and innere Bauart, Leipzig, 

 1852, Bd. I. p. 165. 



