ALPINE AND ARCTIC FLORAS. 



905 



number of species belong to both floras, and are only lacking at the present day in 

 the broad tract interposed between the Alps and the Arctic Regions. But of tliese 

 species common to both floras the majority are distinguished in the Alps by their 

 rarity, and only grow on particular spots here and there on black eartlj or peat, or 

 close to cold springs. Many must be the botanists who have rambled year nft^-r 

 year over the Alps collecting flowers without ever coming across such species aa 

 Saxifraga cernua, Betula nana, Juncus arcticus, and Juncius castaneus, which are 

 common in arctic areas of vegetation but very rare in the Alps, though they may 

 have climbed all the summits high and low, and searched the most sequestered 

 valleys, and, moreover, may possess a thorough knowledge of Alpine vegetation. 

 Similarly, when a Botanist, who has acquired on the spot an accurate knowledge of the 

 Arctic Flora, pays his first visit to the Alps an entirely new world meets his gaze. Not 

 only is the number of species indigenous to alpine regions much larger than that 

 found in the extreme north, but the two floras difier widely in their composition. 

 The very species which are of most common occurrence in the Alps, and wliich con- 

 stitute the ground-work of the communities characteristic of that region, are alien 

 to the Arctic Flora. Such are the extensive meadows of Grasses and Sedges, the low- 

 growing forests of Mountain Pines, Alders, and Dwarf Medlars, the scrub of Alpine 

 Roses (Rhododendrons), and the carpet of prostrate woody plants (Rhamnns pumila, 

 Daphne striata, Salix retusa, S. Jacquiniana), besides many other species which 

 are peculiarly adapted to a substratum of rock or debris, and constitute one of the 

 chief glories of the Alps. To this category we must also add the particular plants 

 which, next to the Alpine Roses, are the most commonly recognized representatives 

 of the Alpine flora, viz. Valeriana celtica, Jleum Mutellina, PHmula Auricula, 

 Artemisia Mutellina, Onaphaliuni Leontopodium (the Edelweiss). , The alpine 

 species of more than 50 genera do not grow at all in the arctic regions, and in the 

 case of many other genera, though both districts possess a few of the species in 

 common, it is just those which are peculiarly characteristic of the Alpine Flora that 

 one seeks for in vain in the extreme north. It would thus be absurd to suppose 

 that such a flora has migrated from the arctic regions to the Alps, and there is much 

 more reason for concluding that the scanty flora of the arctic region was m part 

 derived from the high mountain areas of more southern latitudes. 



Researches into the subject of the distribution of Alpine species and of li.e genera 

 to which they belong have revealed the fact that some alpine plants occur also in the 

 higher parts of the Carpathians, in the Caucasus, in the Altai Mountains, and even in 

 the Himalayas, whilst others are found in the Abruzzi and the Balkans, and upon these 

 data might be based the hypothesis that the alpine flora was derived from the east 

 and south, and migrated in the Diluvial Period from the Himalayas, the Cauca.su.s 

 or the Abruzzi to the Eastern Alps. But the same facts might equally well lead any 

 one who made a similar investigation of the Alpine flora of the Cauca.sus or the 

 Himalayas to infer that the plants in question had travelled thither from the Alps. 

 I believe that all such hypotheses involve one in a circle, and bring one no ncArer to 

 the goal. If we wish to solve the question as to what was the place of origin of 



