FLORA OF SCOTTISH LAKES 
209 
dark water was to kill out the whole of the aquatic flora of the original 
lochs, and the ever-changing level has not favoured the introduction 
of a new flora ; in fact, I doubt if an aquatic flora could exist there 
under the present conditions. Not only were all the aquatic plants 
of the original lochs destroyed, but the entire littoral flora was also 
extinguished by drowning, so that, when the water is low, the 
remains of the old littoral trees and shrubs, which have not yet 
decayed, form a desolate picture of death and destruction. 
Between Loch Mhor and Loch Ness there are a few small lochs 
that are very similar to one another in both their physical features 
and their flora. Their water is usually peaty, and their shores on the 
east side are frequently more or less stony, whilst the western shores 
are generally marshy. Most of them have large associations of 
Castalia speciosa, which, with copiously wooded shores and a general 
luxuriance of vegetation, give them a decidedly lowland appearance. 
The plants, however, notwithstanding the general exuberance of 
growth, are such as are usual to the peaty lochs of this area. On 
the west side of Loch an Ordain there is an extensive marsh, which is 
overgrown with Carex rostrata as the dominant plant. In the middle 
of the marsh, however, there is a circular pool in which the water 
is too deep for the Carex, and one side of this is overgrown with 
Castalia speciosa. Such circular pools, forming a portion of a larger 
loch, are known under the unpleasant appellation of " murder-holes."" 
In the seven Areas described in this paper I have only seen two other 
well-formed holes of this kind, namely, at Loch Kilcheran in Lismore, 
and Loch Neldricken in Kirkcudbrightshire. 
Loch Kemp is beautifully situated amongst hills, some of the 
lower slopes being wooded with birch. The shores are mostly rocky, 
the water is very peaty, and the vegetation is extremely scanty. 
When looking over the side of a boat the bottom is quite invisible 
at a depth of 5 feet. On the north-east side the bottom, within the 
photic zone, is to a great extent incrusted with a hard, brittle layer, 
about half an inch thick, resembling moor-pan ; no plants grow on 
this substance. In other places there is a bottom carpet of Littorella, 
Lobelia, and Isoetes to a depth of 12 feet; beyond this depth 
there are no plants. The other plants observed here are as follows : — 
Callitriche hamulata, Juncus fluitans, Utricularia vulgaris, Potamo- 
geton natans, Castalia speciosa, Equisetum limosum, and Carex rostrata, 
but none of them were abundant. Any other littoral plants were merely 
isolated specimens of common species here and there among the rocks. 
Loch Knockie is about one and a quarter miles long. It much 
resembles Loch Kemp in general features, but its water is less peaty, 
and vegetation is rather more plentiful. The photic zone extends to 
a depth of 25 feet, at which depth Nitella opaca grows. Carex 
14 
