Flora of Scottish Lakes. 
131 
1909-10.] 
these two lochs are as follows : — Subularia aquatica, Lobelia Dortmanna, 
Littorella lacustris, Isoetes lacustris, Myriophyllum alterniflorum, Juncus 
fluitans, Chara fragilis, var. delicatula, Potamogeton prselongus, P. poly- 
gonifolius, P. lucens, P. crispus, P. perfoliatus, Nymphsea lutea, Castalia 
speciosa, Phragmites communis, Scirpus lacustris, Equisetum limosum, 
Carex rostrata, C. filiformis, C. flava, var. lepidocarpa, C. Goodenovii, 
Heleocharis palustris, Menyanthes trifoliata, Comarum palustre, Juncus 
articulatus, J. effusus, Caltha palustris, Galium palustre, Hydrocotyle 
vulgaris, Ranunculus Flammula, Scutellaria galericulata, Narthecium 
ossifragum, Lycopus europseus, Lysimachia vulgaris, Rhynchospora alba, 
Cardamine pratensis, Spiraea Ulmaria, Pedicularis palustris, Mentha sativa, 
Eriophorum polystachion, etc. 
Carlingwark Loch forms a pleasing addition to the prosperous little 
town of Castle-Douglas (fig. 53), imparting an impression of repose to the 
clean and well-ordered streets. It is -f mile long by J mile wide, and 
has a maximum depth of 17 feet, but over a considerable portion of its 
area the depth is less than 8 feet. The surface is 143 feet above sea level. 
The loch is connected with the River Dee by a narrow canal which is 
about 1 1 miles long. This canal was cut for the transport of marl up the 
River Dee, even as far as the Glenkins. Marl was discovered in abundance 
in and about the loch, and was formerly in great demand by agriculturists 
for fertilising their land, instead of lime. There are several islands, wooded 
with poplars, willows, alders, etc., which add to the picturesque appearance 
of the loch. An unpleasing feature is that the sewage of the town is 
drained into the loch, which, although about 105 acres in extent, is very 
shallow except at the sites of the old marl-pits, so that in hot, dry summers 
the residents of the town are inconvenienced by unpleasant odours and 
the risk of disease. The water at the south end is fairly clear and bright, 
but at the north end it is somewhat turbid and dead-looking, which is 
probably the result of the drainage from the town. The vegetation also 
has doubtless been affected thereby, for the semi-aquatic flora is composed 
of a large number of species, most of which grow in great luxuriance (figs. 
54-56), whilst the submerged aquatics, although extremely abundant, are 
restricted in variety, possibly because the abnormal abundance of food-salts 
in the water, combined with the general shallowness of the loch, has 
favoured the excessive increase of a few species to the exclusion of others. 
I have, in fact, seen few lakes with such exuberant vegetation. The margin 
is frequently marshy and overgrown with a dense growth of reed or sedge, 
particularly in the south portion of the loch (figs. 55 and 56). At other 
places, especially at the northern end, the flat shore is either stony or of 
