FLORA OF SCOTTISH LAKES 
197 
Glen Moriston. Crossing the picturesque Glen Urquhart, we visit 
the sheets of water to the north. Then passing eastwards at the 
north end of Loch Ness, we inspect a series of lochs on the hills to 
the east, working our way southwards towards Carn sC Chuilinn, and 
finishing the tour at Fort Augustus. The original paper contains 
102 illustrations of the lochs, etc., of this area. 
Loch Ness is the largest fresh-water loch in Scotland ; it is 24 
miles long by f of a mile to 2 miles broad. It is also one of the 
deepest of the Scottish lakes, and drains an area of nearly 700 square 
miles. Its surface is 52 feet above sea-level. It is situated in a 
depression, with mountains rising almost precipitously from its waters 
on either side, throughout its whole length. At the north-east and 
south-west ends, however, the land is low-lying and comparatively 
flat, being, in fact, the strath, or bottom of the valley, known as the 
Great Glen, that bisects the Highlands from Loch Linnhe to the 
Moray Firth. The lower slopes of the adjacent mountains are 
abundantly clothed with forest to the water's edge. This sylvan 
scenery, associated with the effect produced by other plant formations 
on the mountains above, combined with occasional crags of grey 
or red rock boldly projected, gives this superb sheet of water a 
magnificence of its own that can seldom be surpassed. Abundant 
and beautiful as is the terrestrial flora, that of the water is extremely 
scanty ; the causes which bring about this paucity have already been 
mentioned. One may traverse miles of the shores of this lake and 
find scarcely an aquatic plant, unless it be the lithophilous Bryophyta 
or Algas, that defy the erosive power of the waves to remove them 
from the rocks. The only places in Loch Ness where aquatic plants 
are abundant are Urquhart Bay, Inchnacardoch Bay, about the south- 
west portion from Borlum to the railway pier, where the water is 
comparatively shallow, with a pebbly, sandy, or muddy bottom ; also, 
but more scantily, about the estuaries of the rivers Moriston and 
Foyers, and in a few small sheltered bays here and there about the 
lake. Generally the shore is so steep that deep water occurs close to it. 
Opposite Invermoriston, for example, a depth of 652 feet occurs at 
120 yards from the shore. This great depth so near the shore is, of 
course, exceptional, but it serves as an example to show the impossi- 
bility of there being an abundant bottom flora of the higher forms 
under such circumstances. Owing to the matter held in solution by 
the water, the photic zone, throughout which there exists sufficient 
light for the proper development of the higher plants, does not extend 
in this loch beyond a depth of about 30 feet. It therefore follows 
that, on account of the steepness of the sides, the limit of depth for 
the higher plants is reached, as a general rule, within a few feet of 
the shore. Then it must be remembered that everywhere, except in 
