28 A MONTANE RAIN-FOREST. 



from the point of view of their departure from them. So far as con- 

 cerns their relative area, the Slope Forests far exceed the other types, 

 but their characteristics and vegetation are intermediate between those 

 of the ravines and the ridges, and they do not possess the interest of 

 either of the latter habitats. 



WINDWARD RAVINES. 



The ravines and valley bottoms of the Windward Slopes exhibit to 

 the highest degree all those features of vegetation and climate which 

 find expression in the term "rain-forest," although they exhibit quite 

 as strongly as do the other habitats the montane features which dis- 

 tinguish the entire region from the lowland rain-forests. In the 

 ravines, at least, are trees of stately size, forming a more or less con- 

 tinuous canopy beneath which under-trees and shrubs form thickets 

 varying in density according as the main forest canopy is more or less 

 open. The floor of the forest is covered with terrestrial ferns or 

 flowering plants, which, in turn, vary in their stand with the density 

 of the shrubbery and under-trees above them. Throughout the lower 

 levels of the forest garlands of golden-brown mosses species of Phyl- 

 logonium and Meteorium clothe the large trunks and hang from every 

 twig in the undergrowth. On leaning trunks and horizontal limbs are 

 crowded colonies of epiphytic ferns, orchids, and other flowering plants, 

 from which hang pendant fronds of Hymenophyllum or Elaphoglossum. 

 In one spot the terrestrial herbaceous vegetation will far exceed the 

 epiphytic ; in another masses of epiphytes may be found growing above 

 a nearly bare forest floor, or again the epiphytes may be crowded out 

 by the profuse growth of the climbing Marcgravia. Tree-ferns are 

 abundant, standing singly or in groups, either beneath the shade of the 

 largest trees or exposed to the sky. Their trunks form the support for 

 climbing ferns and for masses of the most hygrophilous of the filmy 

 ferns. 



A rather limited number of species of trees and shrubs, together with 

 a relatively small number of herbaceous flowering plants, mingle with 

 a large number of ferns, lycopods, mosses, and hepatics to constitute a 

 type of forest which is far less rich in species and somewhat less rich 

 in individuals than the best-developed lowland rain-forest. Varying 

 greatly from spot to spot in the arrangement of its component species, 

 the forest also exhibits a common tropical characteristic in the abund- 

 ance in one spot of a species which may be rare for miles around. 



No picture of the Leeward Ravine forests is complete which does 

 not portray the floating fog, in which it is enveloped so much of the 

 time, and the reeking wetness which keeps its pads of mosses and hepa- 

 tics always saturated and its foliage continously wet for days at a time. 

 The height and constancy of the atmospheric moisture are the most 



