PROCEEDINGS OF THE SOCIETY. Ill 



Highlands was then briefly described, and it was pointed out 

 that there were certain areas in the Highlands very much richer 

 in alpine plants than others; thus, on a series of mountains 

 stretching from Ben Lui, on the confines of Perthshire and 

 Argyllshire, north-eastwards through Meall-Ghaordie, and along 

 the ridge bounding the north of Loch Tay, and including such 

 high peaks as Craig-na-Caillich, Meall-nan-Tarmachan, Beinn 

 Ghlas, and, highest of all, Ben Lawers, and from Breadalbane 

 north-eastwards into Clova, we find an exuberant development of 

 alpine plants. This tract of ground was defined as the Ben 

 Lawers ridge. The alpine character of the plants on this series 

 of mountains had long been well known, and accurate records 

 had been made of the different species. The second group of 

 mountains begins also at Ben Lui, and stretches northwards by 

 the heads of Glen Lochay and Glen Lyon, and includes the 

 following mountains : — Cam Chreag, Creag Mhor, Beinn Heas- 

 garnich, and others. This was defined as the Mamlorn ridge. 

 The flora of this ridge had not been worked to the same extent 

 as that of Ben Lawers, but what plants had been gathered 

 tended to show that the mountains approached very closely to 

 the Ben Lawers type. 



Before proceeding to discuss the present distribution of the 

 alpine plants in the Highlands, the much wider subject of the 

 origin of the alpine flora was discussed in some detail. It was 

 pointed out that the tendency of recent investigation was to 

 show that it had survived that period of intense cold in the 

 British Isles. It was also contended that the migration of 

 these plants could only have taken place by means of a land 

 connection, and that the alpine flora was at first a lowland 

 flora which was driven inch by inch and yard by yard to the 

 hills, and eventually to the highest mountains. 



In concluding, the present distribution of the alpine flora in 

 the Highlands was dealt with, and it was shown that the richest 

 mountains, namely, those on the ridges just described, coincided 

 with the outcrop of a certain group of schists known geologically 

 as the Ben Lawers phyllites. The minute structure and chemical 

 composition of the schists were described, and it was shown 

 that the structure known geologically as ausweichung , or strain 

 slip, was perhaps the most important factor in determining the 



