308 ZONES AND REGIONS [Pt. Ill, Sect. I 



Jagera, Hopea. In the case of European forest trees, on the other hand, 

 higher grades, usually 5-8, of branches prevail (Wiesner). 



' Even in the largest trees I have seen in the tropics, the number of grades 

 of branches never exceeded five (Ficus elastica, which has often only two to four, 

 F. religiosa, Pterocarpus indica, Altingia excelsa, Grevillea robusta). The numerous 

 observations of Koorders lead to the same result ; exceptionally, however, higher 

 grades of branches occur. The complication of the branching concerns only the 

 twigs that immediately bear the foliage. Those portions of the axes that have 

 become leafless are throughout only feebly branched.' 



The leaves of the trees in the rain-forest are highly diversified, frequently 

 of firm leathery consistence and very glossy, but seldom are they 

 finely pinnate or felted with hairs. They are, as Wiesner has explained 

 in detail 1 , usually set obliquely as regards the zenith, often aggregated 

 in tufts at the ends of long bare axes (Fig. 145). 



The shrubs of the rain-forest, like the trees, are for the most part 

 sparsely branched when compared with the shrubs of the forests of Central 

 Europe. Their leaves are usually large, delicately membranous, seldom 

 coriaceous. 



ii. TERRESTRIAL HERBS OF THE RAIN-FOREST. 



The terrestrial herbs (Figs. 135, 136) are sometimes erect, sometimes 

 creeping, feebly branched, and nearly always provided with elongated axes ; 

 in accordance with the great humidity dense rosettes do not occur. 

 Wherever the shade is denser the soil bears only delicate weeds, which, 

 by their weak roots, their large and excessively delicate leaves, the scanty 

 development of fibres and of vessels in their turgid brittle stems, exhibit in 

 the clearest manner the influence of moisture in both the soil and air. 

 Various Rubiaceae and Urticaceae are illustrations of these features. 



Many herbs growing on the ground of the virgin forest are provided with 

 wonderful markings on their foliage, in the way of white, silvery, golden, or 

 red spots and stripes, which have raised many of them to the rank of choice 

 ornamental plants, like species of Begonia, of Marantaceae, of Orchidaceae. 

 Stahl considered these coloured flecks as devices for increasing transpira- 

 tion. His discussion of this subject is sagacious and suggestive, but, 

 owing to the want of quite conclusive experiments, is still too hypothetical 

 to merit detailed consideration. 



Not unfrequently, particularly in very moist and shady spots, the foliage 

 of the herbs exhibits the velvety surface (Fig. 24), the connexion of which 

 with the concentration of light and furtherance of transpiration has already 

 been described 2 . In similar places, the foliage of many plants, especially 

 species of Selaginella and Trichomanes, glistens with a metallic blue 

 lustre. 



1 Wiesner, op. cit., pp. 73-4. 2 See p. 19. 



