88 COLONSAY 



the Marsh Helleborine Orchis, then practically two new 

 additions to the flora of the West of Scotland. A paper by 

 Mr Somerville on the finding of these plants was afterwards 

 read before the Edinburgh Field Naturalists' and Micro- 

 scopical Society, and before the Natural History Society of 

 Glasgow. His subsequent illness and lamented death 

 prevented the completion of his intended paper on additions 

 to the flora of Colonsay. The writer records with gratitude 

 his indebtedness to the deceased gentleman for much kindly 

 assistance in the earlier stages of this work : his enthusiasm 

 for botany, latterly his favourite pursuit, was inspiring. 



Local Distribution of Plants. The particular situations to 

 which certain plants are confined is not, perhaps, a more 

 striking feature in their local distribution than the indis- 

 criminate manner in which others seem to be scattered 

 throughout the island. Unlike the loftier of the islands, 

 the elevation (500 feet) is not sufficiently great to affect 

 perceptibly the distribution of plants, the same species 

 frequently growing both at sea-level and on the summits 

 of the hills. Many plants which are affected by exposure 

 trees, etc. are only to be seen in sheltered positions, 

 more commonly on the eastern half of the island. Others 

 Chickweed,. Cleavers, Sow-thistle, Herb Robert, Dock, 

 Silverweed, Stonecrop, etc. are found growing down to 

 high-water mark and in various situations inland. Some of 

 the commonest sea-rock plants Sea-pink, Sea Plantain, Sea 

 Spleenwort, and Sea Campion reappear on rocks near the 

 centre of the island. Though many species Willows, Grasses 

 (Agrostis alba, etc.), Sedges (Car ex Goodenotvti, etc.), Am- 

 phibious Buckwheat, Dock, etc., seem to be equally well 

 at home in very marshy and in comparatively dry situations, 

 the most important factor locally affecting the distribution 

 of plants, nevertheless, is the condition of the ground as 

 regards drainage. From the geological formation it is seen 



