and Irish mountains, but on the margins of continental glaciers as well. On the Faulhorn, in the canton of Berne, at 9,000 feet above the sealevel, there grow one hundred and thirty-two species of flowering plants of which fifty-one are common to Lapland and eleven to Spitzbergen. In the Engadine, a high valley in the canton des Grisons, there are found eighty species of plants unknown to the rest of Switzerland, but which are very common within the Arctic circle. Taking the Alpine flora of Switzerland as a whole, we discover that out of a total number of three hundred and sixty species, one hundred and fifty-eight are common to Scandinavia and northern Europe generally. The relation of the European Alpine flora to that of the Arctic regions may also be seen by reversing this comparison. Thus, out of six hundred and eighty-five species of flowering plants found in Lapland, one hundred and eight are also known as growing on the Swiss Alps. The extension of the Arctic flora southerly, during the Glacial period, obtained as far as the Pyrenees, where we meet with sixty-eight species of plants common to Scandinavia.

Darwin describes the origin of our Alpine flora in a similar way. Speaking of the close of the "Great Ice Age," he says:-"As the warmth returned, the Arctic forms would retreat northwards, closely followed up in their retreat by the productions of the more temperate regions, and as the snow melted from the bases of the mountains the Arctic forms would seize on the cleared and thawed ground, always ascending as the warmth increased, and the snow still further

disappeared, higher and higher, whilst their brethren were pursuing their northern journey. Hence, when the warmth had fully returned, the same species, which had lately lived together on the European and North American low-lands, would again be found in the Arctic regions of the Old and New Worlds, and on many isolated mountain-summits far distant from each other."

"Thus we can understand the identity of many plants at points so immensely remote as the mountains of the United States and those of Europe. We can thus also understand the fact that the Alpine plants of each moutain-range are more especially related to the Arctic forms living due north or nearly due north of them; for the first migration when the cold came on, and the re-migration on the returning warmth, would generally have been due south and north. The Alpine plants, for example, of Scotland, as remarked by Mr. H. C. Watson, and those of the Pyrenees, as remarked by Ramond, are more especially allied to the plants of Northern Scandinavia ; those of the United States to Labrador; and those of the mountains of Siberia to the arctic regions of that country. In like manner it will be found that the Alpine plants of all our highest English hills and mountains are related to those of Scotland and Scandinavia; or rather (and here we also include the Alpine flora of Wales and Ireland) they have the same common origin.

Can the reader now marvel that so many of our mountain flowers are clothed with new wonder for a thoughtful botanist? They have found a refuge from

the low-land climatal invasions in those very highlands where the aboriginal Britons also sought shelter from the overwhelming encroachments of Roman, Saxon, Dane, and Norman ; and the old British

MOUNTAIN AVENS (Dryas
octopetala).

speech is heard as Cymric, Gaelic, or Erse, chiefly in the very mountains where floral refugees also sought and obtained an uncontested freedom.

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Let us now proceed to note the more markable of these Alpine plants. Although some of them are exquisitely beautiful, others are very simple and unpretending.

But even this scanty, historical Alpine flora has its likes and dislikes. Where the mountains are formed of Carboniferous limestone we may expect to find the white Mountain Avens (Dryas octopetala), whose woody

stem and pretty crenated evergreen leaves (resembling those of the oak, whence its generic name), often completely mat the ground where it takes up its abode. Nowhere have we seen it growing in such

luxuriance as on the limestone hills which terminate in the bold cliff of Black Head, in the west of Ireland. It is also found in Wales, Scotland (where it ascends to a height of 2,700 feet), and the tops and flanks of the limestone hills in the West Riding of Yorkshire. Professor Kerner has recently pointed out the purpose of leaves of the character possessed by the Mountain Avens. He says: "In many plants the foliage is of thick and leathery consistence, and this acts as a security against injury from cattle. The wide tracts in the Alps which are seen covered with evergreen carpets and shrubby thickets of Azalea procumbens, Dryas octopetala, Empetrum, &c., and other characteristic plants, are avoided by sheep, and also by chamois. It is exceptional to find the leaves of these plants mangled by grazing animals, and we never find them completely destroyed." The rambler cannot fail to recognise this flower from its eight snow-white petals. Chief among these cold-loving plants is represented the genus Saxifraga, literally "stone-breakers," from the old belief (based on the rocky habitats of so many species) that the roots of some of these plants could penetrate the hardest rocks. At least seven species of this plant are characteristically Alpine or sub-Alpine. We never find them except on elevated regions, and there under slightly different conditions. Thus Saxifraga stellaris loves to grow beside the cool mossy mountainsprings and rills, where its starry white flowers can be easily recognised from their resemblance to that rare but indigenous plant which English cottagers delight to use for the borderings of their gardens,

the elegant "London Pride" (Saxifraga umbrosa). This latter plant was thought to be indigenous only on the mountains of south-western Ireland, where it is known among the natives by the name of "St. Patrick's Cabbage." Recently, however, it has been found growing on the hills about Settle, in the West Riding, and there cannot be the slightest doubt it is truly indigenous to this new locality. Another of the commoner mountain Saxifrages bears bright yellow flowers, whose petals are richly adorned with orange-coloured spots, on downy and glutinous stalks (Saxifraga aizoides). This species ought to be looked for in the stony places beside the Alpine rills. Both it and S. stellaris are exceedingly abundant along the wayside as we cross the top of Kirkstone Pass, to descend into the valley of Brotherswater. The stellaris is abundant beside rills everywhere in North Wales at a certain height, but the Yellow Saxifrage has not as yet been found in that country. The latter is extraordinarily abundant in the Highlands, sometimes covering large spaces with its crowded linear leaves.

Rarer species of Alpine Saxifrages are limited to certain mountains, as the Purple Saxifrage (S. oppositifolia), whose solitary, bright purple flowers love to grow in dark places on the crags of Snowdon, and on the tops of the highest cliffs of the Highland mountains, to an altitude of 4,000 feet. Not far from it (for this plant loves the same inclement exposure) may be found Saxifraga nivalis, easily recognised, not only by its many white blossoms, but also from its leafless stem rising from the leathery leaves. It