186 JAVA. [chap. vii. 



birds in so effectually stocking these Alpine heights is 

 equally out of the question. The difficulty was so great, 

 that some naturalists were driven to believe that these 

 species were all separately created twice over on these 

 distant peaks. The determination of a recent glacial epoch, 

 however, soon offered a much more satisfactory solution, 

 and one that is now universally accepted by men of science. 

 At this period, when the mountains of Wales were full 

 of glaciers, and the mountainous parts of Central Europe, 

 and much of America north of the great lakes, were 

 covered with snow and ice, and had a climate resembling 

 that of Labrador and Greenland at the present day, an 

 Arctic flora covered all these regions. As this epoch of 

 cold passed away, and the snowy mantle of the country, 

 with the glaciers that descended from every mountain 

 summit, receded up their slopes and towards the north 

 pole, the plants receded also, always clinging as now to 

 the margins of the perpetual snow line. Thus it is that 

 the same species are now found on the summits of the 

 mountains of temperate Europe and America, and in the 

 barren north-polar regions. 



But there is another set of facts, which help us on 

 another step towards the case of the Javanese mountain 

 flora. On the higher slopes of the Himalaya, on the tops 

 of the mountains of Central India and of Abyssinia, a 

 number of plants occur which, though not identical with 



