The Malay archipelago : the land of the orang-utan ... - Wallace Online

VII.] JAVA. 91or ten of Rubiis, and species of Primula, Hypericum, Swertia,Convallaria (Lily of the Valley), Vaccinium (Cranberry), Rhododendron,Gnaphalium, Polygonum, Digitalis, (Foxglove),Lonicera (Honeysuckle), Plantago (Pdbgrass), Artemisia (Wormwood),Lobelia, Oxalis (Wood-sorrel), Quercus (Oak), and Taxus(Yew). A few of the smaller plants (Plantago major and lanceolata,Sonchus oleraceus, and Artemisia vulgaris) are identicalwith European species.The fact of a vegetation so closely allied to that of Europeoccurring on isolated mountain peaks, in an island south of theEquator, while all the lowlands for thousands of miles aroundare occupied by a flora of a totally different character is veryextraordinary, and has only recently received an intelligibleexplanation. The Peak of Tenerifle, which rises to a greaterheight and is much nearer to Europe, contains no such Alpineflora ; neither do the mountains of Bourbon and Mauritius. Thecase of the volcanic peaks of Java is therefore somewhat exceptional,but there are several analogous, if not exactly parallelcases, that will enable us better to understand in what way thephenomena may possibly have been brought about. The higherpeaks of the AIjds, and even of the Pyrenees, contain a numberof plants absolutely identical with those of Lapland, but nowherefound in the intervening jDlains. On the summit of the WhiteMountains, in the United States, every plant is identical withspecies growing in Labrador. In these cases all ordinary meansof transport fail. Most of the plants have heavy seeds, whichcould not possibly be carried such immense distances by thewind ; and the agency of birds in so effectually stocking theseAlpine heights is equally out of the question. The difficulty wasso great, that some naturalists were driven to believe that thesespecies were all separately created twice over on these distantpeaks. The determination of a recent glacial epoch, however,soon offered a much more satisfactory solution, and one that isnow universally accei^ted by men of science. At this period,when the mountains of Wales were full of glaciers, and themountainous parts of Central Europe, and much of Americanorth of the great lakes, Avere covered with snow and ice, andhad a climate resembling that of Labrador and Greenland at tliejDresent day, an Arctic flora covered all these regions. As thisepoch 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 i^lantsreceded also, always clinging as now to the margins of the pei'-petual snow line. Thus it is tliat the same species are now foundon the summits of the mountains of temperate Europe andAmerica, and in the barren north-polar regions.But there is another set of facts, which help us on anotherstep towards the case of the Javenese mountain flora. On tliehigher slopes of the Himalaya, on the tops of the mountains ofCentral India and of Abyssinia, a number of plants occur which.