CHAPTER IV 



MOUNTAIN FAUNAS 



The animals of mountain and plateau regions show 

 some interesting conditions which make it worth while 

 to consider them separately. Taking mountains first, 

 we may note that elevated ranges may be divided into 

 three regions, each of which presents peculiar biological 

 features. The lowest region is usually clad in forests, 

 conifers predominating as we ascend. At a point which 

 varies with the exposure, the slope, and other factors, 

 even on a single mountain, tree growth ceases, and there 

 comes a zone with steppe characters. The width of 

 this band and its nature vary greatly. In e.g. the 

 mountain regions of Europe, it is characterized by the 

 growth of relatively small herbaceous plants, often with 

 large and gorgeously coloured flowers, but with tufted 

 leaves and other indications of checked vegetative 

 growth. Many of these plants reappear ia the Arctic 

 tundra, but the fact that they are specially abundant 

 in the Alps has led to them being called Alpine plants, 

 whether they occur in the Alps proper, on the hills of 

 Scotland or Norway, in the Himalayas, or in the Cau- 

 casus. 



In tropical regions, e. g. ia Africa, this steppe area 

 with its Alpine plants is replaced by a band where the 

 plants show desert characters ; the Lobehas, Senecios, 

 and tree-heaths of the upper zone of Ruwenzori and 

 Mount Kenya form good examples. In aU regions where 

 the mountains attain sufficient elevation, above the 

 steppe or desert zone comes that of eternal snow, where 



