45 



plants, is quite absent a fact possibly to be attributed to the warm well- 

 drained soil of disintegrated granite and the even conditions of illumination 

 with less direct exposure to wind. The " Nebelwald " of the German 

 botanists, described as predominating on the mountains of the north-east, 

 with trees swathed in lichen, is absent, also the " Krlippelwald" association, 

 while the turgid vegetative form of mossy forest is limited in incidence. 



But, of course, so far as the two former associations are concerned, the 

 lower altitude is a possible and limiting factor. 



6. PTERIDOPHYTIC AND BRYOPHYTIC FLORAS ARE MORE POLYNESIAN 

 THAN MALAYAN IN INCIDENCE AND LUXURIANCE. 



The Pteridophytes and Bryophytes of the Arfak proved exceedingly 

 varied and luxuriant in incidence, more Polynesian than Malayan in facies, 

 but endemic Papuan in type. In mosses Spiridens, with a limited distribu- 

 tion in Polynesia, and since recorded from the north-east and north-west of 

 New Guinea and Borneo, is probably a Papuan generic type. 



6. OPEN " OPPORTUNITY " PLANT ASSOCIATION. 



In a mountainous forest country like New Guinea, sparsely inhabited, 

 with little or no intercommunication between the different tribes, and no 

 migratory herds of grazing animals, there is everything to conserve and 

 nothing to modify natural conditions. 



Lying in what may be called the centre of the monsun region, the whole 

 country is subjected to a more or less regular rhythm of alternating air 

 currents. Beccari (12, i. 216) has emphasized that the north-east monsun, 

 blowing regularly from November to April, must affect the general distribu- 

 tion of plants in the regions which come under the immediate influence of 

 these prevailing winds. This opinion has been already advanced by myself, 1 

 and later 2 from observations on the granite core of the exposed summit of 

 Kinabalu, before I had seen Beccari's convincing remarks in relation to his 

 own observations throughout Malaya. 



Beccari aptly remarks that seeds are lighter than grains of sand from 

 volcanoes, and are adapted to remain longer in the air. Authenticated 

 instances of the possibilities of long-distance transport of grains of sand and 

 volcanic ash by the agency of wind are quoted by him (12, i. 216-220). 

 Warming 3 advances the same theory, for which extraordinary proof is 

 forthcoming in recent work of the Geological Survey of India. La Touche 4 



1 L. S. Gibbs, " A Contribution to the Montane Flora of Fiji, with Ecological Notes," 

 Journ. Linn. Soc., Bot. xxxix. (1909) 137. 



2 . " A Contribution to the Flora and Plant Formations of Mt. Kinabalu and the 



Highlands of Brit. N. Borneo," I. c. xlii. (1914) 47. 



3 T. Warming, ' History of the Flora of the Faeroes,' Botany of the Faeroes II. Copen- 

 hagen, 1903. 



4 T. H. D. La Touche, Mem. Geol. Surv. Ind. xxxv. (1902) 42. 



