II. ASCENDING ZONES. 19 
Scotland, where plants of an alpine character are found descending 
to the sea level or sea shore, such as Thalictrum alpinum, Draba 
incuna, Savifraga oppositifolia, Arbutus alpina, and Dryas octopetala, 
Secondly, all other spaces in any parts of the island, where the 
elevation of the ground leads to the production of the same or 
usually associated species; Arbutus Uva-Ursi, Saxifraga stellaris, 
Alchemilla alpina, Tofieldia palustris, Luzula spicata, and Juncus 
triglumis being examples of the latter. Thirdly, those tracts of 
slight elevation, upon which a corresponding flora ‘and general 
vegetation prevail, apparently in consequence of simple proximity 
to the high mountains; Sawxifraga aizoides growing so low as 300 
feet among the mountains of Cumberland, and Epilobium alsini- 
folium at 500 or 600 feet in Carnarvonshire ; although these 
plants are never seen at so low an elevation in the English 
counties remote from the higher hills. In addition to the species 
mentioned, which are to be regarded as descending from the 
Arctic into the Agrarian region, this upper zone of the latter 
region is characterised by the presence of Ilex, Quercus, Fraxinus, 
Lonicera, Crategus, and the fruticose Rubi, which can scarcely be 
said to occur above the limits of cultivation or of Pteris aquilina ; 
equally so, by the absence of other species which are not seen 
truly wild until we descend into the next lower zone. 
The Mid-agrarian zone will comprehend all the low grounds, 
clear from the mountains, which are situate between the estuaries 
of the Clyde and Tay, on the north, and those of the Humber and 
Dee, on the south; also, a narrow coast tract of the East High- 
lands, extending from Perth to Aberdeen. ‘To this space is to be 
added a narrow belt winding around and amid the hills of Wales, 
and characterised by the vegetation of the present zone, rather 
than by that of the zones above or below this intermediate one. 
The higher hills of Wales rise to the Arctic region; and as the 
surrounding coast line and low grounds inland belong to the 
lowest Agrarian zone, the middle and upper Agrarian zones will 
be found represented above the bases and below the summits of 
the Cambrian hills. In descending from the Super-agrarian into 
the present zone, we find some of its characteristics in the first 
