236 ANNALS OF SCOTTISH NATURAL HISTORY 



The limestone outcrops are easily followed on the range 

 by the fruiting of Bryum alpinuvi, which moss, though 

 common all over the range, seems to fruit only on limestone 

 rocks, this being the case even in Finlarig \Yoods. 



Speaking from a general point of view regarding the 

 number of alpine species found on schistose rocks, and 

 especially on the micaceous schists so abundant on this 

 range, one is apt to infer that these play an important part 

 in the distribution of alpine plants. A well-marked band of 

 schistose rock known by the name of sericite which traverses 

 the upper portion of the range is considered by certain 

 geologists (and their conclusions have been favourably 

 received also by some botanists) to be the substratum most 

 affected by the alpine plants. Some have even gone the 

 length of asserting that the presence of this schist is a 

 necessary part of their environment. These schists are 

 finely laminated, contorted, and lying at all angles, thereby 

 forming a good foothold for plants, even to the fine lamin- 

 ated dust of their decomposed parts so well adapted for 

 retaining the moisture and affording a suitable nidus for 

 the smaller and simpler forms of vegetation. A larger 

 experience of alpine localities, however, urges one to the 

 conclusion that nidus is, after all, only a secondary matter. 

 Climate and exposure seem to be the great factors in all 

 plant life. You may find plants on the schists you do not 

 find on the shales, and others on the granite that you do 

 not find on either, or vice versa, but this can very often be 

 determined by exposure in the case of flowering plants and 

 by moisture in the case of hepatics. 



During the last three years Mr. Macvicar has devoted 

 some time to the investigation of the north-east part of the 

 range, and in the following list his name will be found 

 attached to those species which have been gathered by him, 

 and which I had not previously collected, or had not been 

 able to identify. I have also been fortunate enough to find 

 a number of species not noted by Mr. Macvicar, and this, I 

 think, goes to prove that the district under review is not 

 yet exhausted, of which indeed I feel very confident. This 

 remark holds good, without doubt, as regards the smaller 

 species, and possibly among the larger species also where 



