April 1902.] BOTANICAL SOCIETY OF EDINBURGH 221 



western types, but the former greatly preponderates. Only 

 about one-fourth part of our Atlantic species occur, and 

 then are mostly in small quantity. I include Lcjcunea 

 pateiis with these, but I cannot consider it as a species 

 distinct from L. serpijllifolia. The small typical plant 

 which is confined, or almost so, to the west side of the 

 country, where it is common, is distinct enough, but when 

 it extends eastwards, and even in some of its forms on the 

 west coast, one frequently meets with plants which, in my 

 opinion, are indistinguishable from the small form of 

 L. serpyllifolia. None of its characters are constant, either 

 separately or when looked at as a whole : the size of 

 stipule and postical lobe, the shape and direction of antical 

 lobe, as well as its size and amount of chlorophyll, the 

 manner in which it diverges from the postical lobe, the 

 crenulation and height of wings of the perianth, and the 

 intricate l)ranching of the stems — are all characters which 

 can be matched in some forms of L. serpyllifolia. In the 

 same manner, the characters which separate the small form 

 of L. serpyllifolia from the large form can be seen in many 

 intermediate forms, but in the case of L. fatens, we have a 

 plant to a considerable extent constant in its form within 

 a certain geographical area, and I think it is thus entitled 

 to sub-specific or, at least, varietal rank. Saccogyna 

 viticulosa is the most noticeable of the Atlantic species of 

 the district ; it is confined here, as elsewhere when 

 occurring in the centre of Scotland, to shaded ravines, and 

 is not seen on exposed rocky banks, as is frequently the 

 case on the west coast. 



Few alpine species are to be found below 2500 ft., 

 except on Creag-an-Lochan, where moist shaded rocks 

 descend to 1800 ft. From 2500 to 2800 ft. on most of 

 the hills, and to about 3300 ft. on Ben Lawers, most of 

 the rare species occur which affect wet ground, as the side 

 of rills and marshy places. Above this to the summits, 

 the ground is mostly bare humus, wliich is the favourite 

 site for several of the rarer plants, such as the small species 

 of Acolea and Marsupella. Some species, which are almost 

 confined when on the lower ground to rocks, are to be found 

 on this humus, and in this position generally have longer 

 stems and grow in larger patches. On the east side of 



