CONTENTS xxvii 



SECTION IV. MOUNTAINS 

 CHAl'TKR I. I'HIi MOUNTAIN CITMATE 



PAGES 

 I. Rarefaction of the Air. Diniiiuition in tlie 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. Nocturn.-il 

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

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

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

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

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



CHAPTER II. REGIONS OF VEGETATION 



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

 and diagnoses of the tliree regions — basal region, mont-ine region, alpine region. Comparison 

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

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

 Hlountain-dt'St-rt. .Sequence of woodland climatCj 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. Tlie Features of Alpine Plants. 

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

 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 natur.al alpine vegetation, iii. The 

 Oeeurrenee 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 ipper limit of Plant-life in High Mountains. Saussurea tridactyla . 701-720 



CHAPTER III. MOUNTAIN REGIONS IN THE TROPICS 



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

 districts. Alpine region. Elfm-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. Kilimanfaro accord- 

 ing to Volkens. Xerophilous character of its basal region. Temjierate r.Tin-forest in its mon- 

 tane legion. 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. Me.xico. Xerophilous character of the basal 

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

 the montane region. Aljiine region, iii. Brazil. Coast mountains. Itatiai.i-assu. Serra do 

 Picu 721-749 



CHAPTER IV MOUNTAIN REGIONS IK THE TEMPERATE ZONES 



Introduction, i. The Regions in the Warm Temperate Districts resembling the 

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

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

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

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

 wastes. Alpine region : Elfin-wood. Alpine stony desert. Cushion-plants. i i. .4frica. 



