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, mostly clothed with 
bracken and grass associations (fig. 15). 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 scarcity of rank Molinia about 
the neighbourhood of this loch, I was anxious to discover t6 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 Menyantlies 
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 § mile wide, at an elevation of 690 feet above sea 
