CONTENTS xxvii 



SECTION IV. MOUNTAINS 

 CHAPTER I. THE MOUNTAIN CLIMATE 



PAGES 



i. Rarefaction of the Air. Diminution in the atmospheric pressure with increasing 

 altitude above the sea. Simultaneous diminution in the temperature of the air and increase in 

 the radiation of heat. Unequal temperature in the sun and shade on mountains. Nocturnal 

 radiation. Increased intensity of light. Mountain light richer in highly refrangible rays. 

 2. Atmospheric Precipitations. Increased rainfall as altitude increases. Level of the 

 greatest rainfall. Reduced rainfall above this level. Perpetual snow. Cloudiness. Reduction 

 in water-vapour at great altitudes. Rapid alternation of moistness and dryness of the air. Great 

 intensity of evaporation in the mountain climate . ....... 690-700 



CHAPTER II. REGIONS OE VEGETATION 



i. Climatic Factors causing the Differentiation of Regions. Distinctive features 

 and diagnoses of the three regions — basal region, montane region, alpine region. Comparison 

 between mountain-regions and zones. Former exaggeration of the effects of heat. Humboldt's 

 views. 2. Plant-life in Mountain Regions, i. Mountain-woodland. Mountain-grassland . 

 Mountain-desert. Sequence of woodland climate, grassland climate, and desert climate with 

 increasing altitude. Identity of the formations in the basal and montane regions with those of 

 the lowlands. Characteristic habit of alpine formations, ii. The Features of Alpine Plants. 

 Alpine habit. Elfin-tree. Shrubs. Cushion-plants. Rosette-plants. Grasses. Xerophilons 

 structure. Colours, dimensions, scent of flowers. Periodic phenomena. Bonnier's and Kerner's 

 experiments on the influence of the mountain climate on the structure of plants. Influence of 

 individual climatic factors. Assimilation and transpiration in alpine regions. Increase of sugar 

 in nectaries. Application of experimental results to the natural alpine vegetation, iii. The 

 Occurrence of Alpine Species of Plants in Lower Regions. Occurrence of tropical alpine plants 

 in lower regions as epiphytes and in solfataras. Differences between arctic and alpine plant- 

 structure, iv. The Upper limit of Plant-life in High Mountains. Saussurea tridactyla . 701-720 



CHAPTER III. MOUNTAIN REGIONS IN THE TROPICS 



I. General Considerations. The temperate rain-forest of the montane region in rainy 

 districts. Alpine region. Elfin-wood. Alpine shrub. Alpine steppe. Alpine brushwood- 

 savannah. 2. The Regions in Eastern Asia. i. West Java. Temperate rain-forest. Elfin- 

 wood. Alpine savannah. Alpine steppe, ii. East Java. Temperate savannah-forest of 

 Casuarina. Alpine steppe. Alpine vegetation in sun and in shade, iii. Celebes. Screw-pine 

 forest on Lokon. iv. Borneo. Kinabalu. v. Ceylon. Temperate rain-forest in the montane 

 region, vi. The Nilgiris. 3. The Regions in Tropical Africa. Kilimanjaro accord- 

 ing to Volkens. Xerophilous character of its basal region. Temperate rain-forest in its mon- 

 tane region. Physiognomy and flora of its alpine steppe and desert. 4- The Regions in 

 Tropical America. i. The South American Cordilleras. Temperate rain-forest. Elfin- 

 wood. The paramos. Frailejon. The puna. ii. Mexico. Xerophilous character of the basal 

 region in Central Mexico. Rain-forest. Summer-forest (broad-leaved and coniferous forest in 

 the montane region. Alpine region, iii. Brazil. Coast mountains. Itatiaia-assu. Serra do 

 Picu 721-749 



CHAPTER IV. MOUNTAIN REGIONS IN THE TEMPERATE ZONES 



Introduction. 1. The Regions in the Warm Temperate Districts resembling the 

 Tropics, i. Central Asia. Himalayas. Rain-forest in Sikkim, summer-fo;est on the Western 

 Himalayas. Pamirs. Tibet. Regions on the Xan-Shan according to Przhevalsky. Alpine 

 meadow. Stony desert. Kuenlun forest on the Jakhar. The Tibetan plateau, ii. A r ew Zea- 

 land. Montane region : Xerophilous woodland. Peech-forest. Vegetation of dry grassy 

 wastes. Alpine region : Elfin-wood. Alpine stony desert. Cushion-plants. i i. Africa. 



