112 Proceedings of the Royal Society of Edinburgh. [Sess. 



unequalled south of Perthshire. Mountains rise from the shores almost 

 throughout its whole length, their lower slopes being clothed with either 

 coniferous (fig. 15) or deciduous-leaved trees. This loch somewhat resembles 

 Loch Oich {ante, fig. 40), but is smaller. The water is clear, but slightly 

 peaty. At the west end the margin is formed chiefly by peaty banks ; else- 

 where, except at the east end, which is flat and boggy, the shores are stony, 

 rocky or sandy, or the steep hillside enters the water directly without the 

 intervention of a shore. The upper portions of the adjacent hills, above the 

 tree zone, are, where the rock is not bare of plants, mostty clothed with 

 bracken and grass associations (fig. 1-5). The rank growth of the latter 

 is here, however, much restricted, so that, in comparison with Loch Doon 

 there is but a small quantity of dead vegetation available for covering the 

 loch-bottom. Having noticed the relative scarcit}' of rank Molinia about 

 the neighbourhood of this loch, I was anxious to discover to what depth 

 aquatic plants flourished at its bottom. Careful dredging revealed the fact 

 that the living vegetation here extends to a depth of 16 feet, but at 

 greater depths the dead remains of Molinia, Carex, etc. cover the bottom, 

 and no plants flourish within this zone. The flora of the loch is poor in the 

 number of species, but some of them occur in great abundance. About the 

 west end, at which is the effluent, the loch is narrow, shallow, and bears a 

 considerable marsh vegetation (fig. 14). Beds of Carex rostrata are abundant, 

 and on drier parts of the boggy shore these are gradually or suddenly ex- 

 changed for common bog plants. At the east end the affluent passes through 

 an extensive delta, which is overgrown with marsh plants common to the 

 district (fig. 13). Along the shores, Equisetum limosum is abundant, and 

 here and there occur belts of Phragmites communis and Menyanthes 

 trifoliata, whilst Juncus acutiflorus and J. efFusus are both well represented. 

 The shore rocks, which are not a particular feature of this loch, bear a 

 number of common Bryophytes. The submerged plants are as follows : — 

 Littorella lacustris. Lobelia Dortmanna, and Isoetes lacustris, all very 

 abundant, and forming a dense bottom-carpet. The last mentioned extends 

 to a depth of 16 feet. Utricularia vulgaris is abundant to a depth of 8 feet. 

 Potamogeton pusillus and P. obtusifolius are abundant to 10 feet deep. 

 Potamogeton polygonifolius, a few plants only. Juncus fluitans is extremely 

 abundant, and Batrachospermum moniliforme grows on stones by the shore. 

 Beyond the plants mentioned, the flora is extremely sparse, consisting merely 

 of a few specimens of common species. 



Loch Grennoch, by Cairnsmore of Fleet (not to be confounded with 

 Loch Grenoch or Woodhall Loch near Laurieston), is a fine sheet of 

 water 2 miles long by f mile wide, at an elevation of 690 feet above sea 



