120 Proceedings of the Royal Society of Edinburgh. [Sess. 
Loch Ken is one of the largest lochs in this part of Scotland, being only 
exceeded in size by Loch Doon. It is 142 feet above sea level, and has 
a maximum depth of 62 feet. The loch proper is generally considered to lie 
between the grounds of Kenmure Castle and the Boat-of-Rhone railway 
viaduct ; this portion is 4 \ miles long by \ mile wide in the widest part. 
The River Dee joins the loch a little below the viaduct, and thence the 
combined waters are continued as a narrow lake, in some places, however, 
\ mile wide, considerably to the south of Crossmichael. This lake-like 
portion extends the loch a further distance of over 4 miles, and is usually 
recognised as a part of the River Dee, although to the uninitiated it 
belongs to Loch Ken, and must be considered so from a botanical point of 
view. This sheet of water is thus about 8f miles long : it varies in width 
from 100 yards to 4 mile, and has a drainage area of nearly 300 square 
miles. Like Woodhall Loch, Loch Ken presents a mixture of the highland 
and lowland types, not only in its flora and physical conditions, but also in 
scenic effect, as a comparison of figs. 31 to 40 readily shows. Endowed with 
charming and picturesque surroundings, which are further enriched by 
interesting historical associations, it seems strange that this inviting country 
should attract so small a flow of tourists. In many places the shore 
consists of stones and rocks, which are usually angular or but slightly 
waterworn and afford support to a very scanty flora ; a narrow strip of such 
shore usually passes at once into moor, meadow, or wood (figs. 33, 36, 37). 
In other places the loch is bordered by bog, which makes it difficult to 
distinguish any line of demarcation between land and water (fig. 35). 
More rarely, the shore may be sandy, or the water may be bordered by a 
bank without the intervention of a shore. In that portion of the loch 
above the railway viaduct vegetation seldom occurs at a greater depth than 
6 or 7 feet ; beyond that depth, clay, mud, or vegetable detritus covers the 
bottom, to the exclusion of living plants. In the lower portion, about 
Barton and Crossmichael, there is in places a bottom flora down to a depth 
of 12 feet. This fact is accounted for by the great body of peaty water 
from the River Dee scouring the bottom, and washing the vegetable detritus 
either down stream or into deeper places. 
Near the head of the loch the slight peatiness of the clear water is 
somewhat modified by the drainage received from the villages and culti- 
vated areas through which the Water of Ken flows, and at that part the 
variety and luxuriance of the marsh vegetation affords evidence of a greater 
abundance of food-salts than is usual in peaty lochs. It is also interesting 
to note that Isoetes lacustris, a plant very impatient of water rich in 
normal plant food-salts, was not found nearer the head of the loch than the 
