BRITISH ALPINES. 6i 



almost at sea level, climb up to the region of the British 

 Alpines ; and in the same way some of the latter 

 occasionally descend considerably below their normal 

 altitude. And here it may be well to point out that 

 altitude is not the sole feature in determining the 

 presence, or otherwise, of our native Alpines. That 

 they should decrease in numbers as they pass over the 

 border into Cumberland, and again into Wales is 

 natural ; but there does not at first sight appear to be 

 adequate cause for such a difference between the higher 

 hills of Carnarvonshire and of Brecknockshire. The 

 scantiness of the flora of the Brecknock Beacons is 

 in striking contrast to that of the Glyders ; but whereas 

 the latter have an abundance of stone-strewn surface, 

 with hollows where the winter snow can lay long, and 

 with corries and rivulets, the former are covered with 

 grass almost to the top, with few springs and hardly any 

 crags. It is on the ledges of rocks down which the 

 water trickles, that the flowers grow in the greatest 

 luxuriance ; and on the hills where the mists gather, 

 and the moisture from them keeps the plants well 

 watered. Geological formation also plays its part, 

 and those rocks that more easily disintegrate have the 

 richest flora ; and hence the rocks of the Breadalbane 

 range provide a richer field for the botanist than 

 does the monarch of Scotch mountains with its 

 bewildering mass of granite boulders. 



Most of the chief families of British plants have one 

 or more representatives of Alpines ; in a few cases, the 

 mountain plants form a considerable proportion of the 

 number, and in one at least — that of the Saxifrages, 



