FLOEA OF SCOTTISH LAKES 
201 
dominant plants, namely, Lobelia Dortmanna, Isoetes lacustris, 
Littorella lacustris, Juncus fluitans, and Callitriche hamulata. 
Loch Oich is the highest of the lakes in the Great Glen ; it is four 
miles long, with shores and islands abundantly wooded. Set amongst 
lofty and rugged mountains, it presents a magnificent piece of 
highland scenery. The water is peaty, and, as a considerable area of 
the loch is so shallow that the bottom is within the photic zone, 
there is an abundant submerged flora, although restricted in variety, as 
at Loch Ness. The shores of this loch are stony or sandy, with a 
very sparse vegetation or none whatever. Notwithstanding the 
innumerable small bays and shallow shores, there is very little 
marsh, so that plants of this habit are not abundant. The Calder 
Burn has brought down a great amount of detrital matter into the 
loch, forming large gravel banks, but these are almost destitute of 
plants. The paucity of marsh and shallow-water vegetation in this 
loch must, I think, be due to the abundance of stones and sand and 
scarcity of mud. The hills hereabout are faced with glacial drift- 
gravel, which is brought into the loch by burns and deposited along 
the shores. This gravel is extremely antagonistic to littoral phanero- 
gams, because it is continuously shifting under the power of the waves. 
These long, narrow lochs running in the direction of the prevailing 
winds always have barren shores, owing to the waves having power 
over practically the whole of the loch ; this is more especially the 
case if the shores happen to be of gravel. 
Loch Lochy is not properly in the Ness Area, as it drains into 
Loch Linnhe. Some dredging operations by the Mermaid^ at depths 
of from 100 to 500 feet, furnished exactly similar results to those 
obtained at Loch Ness, namely, non-fetid mud, a limited quantity of 
vegetable detritus, no living plants of the higher types, and a 
restricted number of bacteria and animals of low organisation. 
Beyond this I have only examined the north-east end of the loch, 
which is practically the same in character and flora as Loch Oich ; 
the water, however, is less peaty. The mountains here also are faced 
with glacial drift-gravel, through which the numerous watercourses 
have carved enormous gullies, bringing down the gravel into the loch. 
By this action, two burns upon opposite shores have brought into the 
loch at Kilfinnan almost enough material to divide the loch in twain. 
Lochan Coire Glas, in Glen Garry Forest, is an extremely wild 
little loch about 1600 feet above sea-level. Mountains rise pre- 
cipitously from its margin to over 3000 feet, closing it in on three 
sides like an amphitheatre. Gusts of wind descending the mountains 
strike the loch with terrific force, notwithstanding its apparently 
sheltered position. This loch is gradually being silted up with 
detritus washed in by burns, or rather waterfalls, that descend the 
