ALPINE AND ARCTIC FLORAS. 907 



Fassa Alps in Tyrol. This holds especially in the case of the majority of those 

 species which belong both to the present Arctic Flora and to the present Alpine 

 Flora. Let us suppose the Alpine Flora driven as far as the North of Germany at 

 the time of the greatest distribution of the diluvial glaciers. Extensive glaciers had 

 also advanced far to the south from the north, and had caused a displacement of the 

 flora indigenous to the -Scandinavian Mountains in the Tertiary period as far to the 

 south as Northern Germany. Thus the floras of the north and of the Alps must 

 have met there, and when later the climate again became milder a retreat of the 

 immigrants took place on the one side towards the north, on the other side towards 

 the Alps. On this occasion some species which previously did not occur in the 

 Scandinavian Mountains travelled northward, and some hitherto unknown in the 

 Alps travelled into the Alps. To that epoch must be ascribed the introduction into 

 Germany of several Arctic species, e.g. Alsine stricta, Saxifraga Hirculus, Pedi- 

 cularis Sceptruvi, Statics purpurea, Salix depressa, Betula humilis, and Juncus 

 stygius — which then became dispersed over the low lands lying at the foot of the 

 Alps in Salzburg and Bavaria, though they did not reach the Alpine region, but 

 remained behind on the northern border of the mountain area. 



The remarkable relations above referred to as existing between the Alpine flora 

 of the Alps and those of the Carpathians, the Caucasus, the Altai, and the Himalayas, 

 and also those of the Pyi-enees, the Abruzzi, the Dinaric Mountains, and the Balkans 

 cannot be explained by what took place in the Diluvial period. It has been 

 ascertained by geologists that the first glaciation of the Alps was not more recent 

 than, but was possibly even prior to, the third stage of the Miocene Period in the 

 south-east of Europe, and that during that epoch there could have been no connection 

 between the high mountain flora of the Alps proper and those of the Carpathians 

 and the Balkans, not to speak of the mountains lying further to the east or south, 

 even though the Alpine flora may have descended to a much lower level on the 

 eastern side. The high mountain floras have hardly met one another either in the 

 direction of east and west, or in that of north and south. If, therefore, in the 

 Alps, after the retreat of the glaciers, other species joined forces with those belonging 

 to the Alpine flora which returned once more to higher regions, these were species 

 belonging rather to hilly lowlands. Many such species are able to endure the alpine 

 climate without being injured, and they are represented even at the present day by 

 large numbers of individual plants both in the lowest parts of the valleys and on 

 the heights of the Alps. Thus Erica carnea, Glohidaria cordifolia, and Biscutella 

 laevigata may be traced from the shores of the Adriatic and the banks of Lake 

 Garda, and from the less lofty heights on the border of the Wiener Becken up into 

 the alpine region, and may be looked upon as representatives of the plants which 

 naturalized themselves in that region after the last diluvial ice-age. 



If the kinship of the floras gi'owing on the crests and shoulders of the high 

 mountain chains which succeed one another from west to east and from north 

 to south is not explicable from what took place in the Diluvial period, we must go 

 back to an earlier time when either the mountain ranges now separated from one 



