722 ZONES AND REGIONS [Pt. Ill, Sect. IV 



possess a more massive growth, a richer ramification, smaller and thicker 

 leaves than trees in the tropical rain-forest, Lianes are fewer in number and 

 thinner in the stem ; epiphytes are much smaller, usually herbaceous, and 

 are represented far more by cryptogams (mosses and ferns) than by 

 phanerogams. The extraordinarily luxuriant development of epiphytic 

 mosses exceeds that of the temperate lowland rain-forest, and is to be 

 attributed to the mists prevailing in the montane region. The presence 

 of many closely allied types of plants in the rain-forest of the montane 

 region of tropical mountains, and of the lowlands of higher latitudes, adds 

 a likeness in their flora to the likeness in their oecology. 



The transition from the montane to the alpine region is characterized 

 by a reduction in the size of the trees and in the amount of their foliage, 

 which gradually acquires a pronounced xerophilous structure. The 

 stems become shorter and relatively thicker, the branches longer, the 

 entire growth becomes irregular, the characteristic form of elfin-tree is 

 revealed. 



To the diminutive elfin-wood there succeeds a xerophilous belt of 

 shrub, then alpine grassland prevails, except on rocks and gravels where 

 low woody plants establish themselves. The grassland usually assumes 

 the form of alpine steppe. It consists of tufts of narrow-leaved grasses, 

 the spaces between which are sometimes bare, sometimes occupied by 

 dwarf-shrubs and perennial herbs, and the occurrence of dwarf-trees 

 invests it sometimes with the stamp of a brushwood-savannah. Higher 

 up, on the highest summits, grassland is gradually replaced by alpine desert. 

 Here grass appears hardly anywhere except in moist oases ; dwarf-shrubs 

 and cushion-plants separated by wide gaps make up the scanty vegetation. 

 Some lichens form the last traces of vegetation, for instance on the summit 

 of Kilimanjaro, at 6,010 meters. 



A differentiation of mountain slopes so richly developed as that just 

 described appears in rainy districts only. In a dry climate forest does 

 not appear before the montane region, or is altogether absent, as on the 

 western slopes of the Cordilleras in Peru and Bolivia, where the regions 

 from sea-level up to perpetual snow consist of a series of deserts. 



2. THE REGIONS IN EASTERN ASIA. 



The high mountains of the Malay Archipelago do not reach snow-limit, 

 and do not even raise themselves far into the alpine region. Yet they 

 exhibit a series of well-marked stages of vegetation, and are specially 

 instructive anent the study of the physiological effects of the mountain 

 climate on plants, as they exhibit neither the low temperatures nor the 

 masses of snow on which the chief stress is usually laid in discussing alpine 

 vegetation. 



