160 Proceedings of the Royal Society of Edinburgh. [Sess. 
however, became enlightened regarding the danger of this mode of sewage 
disposal, and forthwith adopted a more modern method. Meanwhile, certain 
colliery owners found in the affluent a convenient means of disposing of 
their mine water as well as the waste from coal-washing machinery, so that 
now the burn resembles a stream of ink, and the loch is being silted up with 
a deposit of coal-dust. The influence of such filthy additions is seen over 
the whole of the loch, particularly at the west end, where the deep, black 
mud has an insufferable odour. When the loch received the sewage, the 
water had a turbid, unwholesome appearance, and was everywhere crowded 
with plankton organisms, besides which all objects about the shores were 
covered with filamentous Algse, chiefly Cladophora fracta, whilst there were 
innumerable floating masses of Enteromorpha intestinalis and Cladophora 
flavescens. Now the water is black and dead-looking, and the Algae have 
considerably diminished, especially the Cladophorae, whilst everything is 
covered with black filth. The marginal vegetation previously mentioned is 
luxuriant, although somewhat restricted in variety, but the submersed 
plants are scarce, which is not surprising when one considers the vicissitudes 
through which the loch has passed. 
The plants of the marshy area in the north-west corner are chiefly as 
follows: — Scirpus lacustris, Equisetum limosum, Heleocharis palustris, 
Carex rostrata, C. Goodenovii, C. paniculata, C. canescens, Menyanthes 
trifoliata, Epilobium hirsutum, Polygonum amphibium, Hippuris vulgaris, 
Phalaris arundinacea, Sparganium ramosum, Comarum palustre, Iris Pseud- 
acorus, Juncus effusus, J. glaucus, J. acutiflorus, Myosotis palustris, Veronica 
Beccabunga, Alisma Plantago, Ranunculus Flammula, R. sceleratus, Epilo- 
bium palustre, Valeriana officinalis, Lysimachia vulgaris, Cardamine 
pratensis, Caltha palustris, Spiraea Ulmaria, Viola palustris, Hypnum 
cuspidatum, etc. There are pure groups of Iris Pseud-acorus standing 5 
feet high out of shallow water, and the same occurs at Loch Fitty. Some 
very large clumps of Cardamine pratensis were also found here. Many of 
these were propagating vegetatively by the production of plantlets from 
buds at the base of the leaflets. This method of reproduction is probably 
in this case due to overfeeding, as the soil is very rich at this corner of the 
loch. I am unable to say whether these plants produce seed as well, because 
when I saw them the season had passed. A beautiful variegated variety 
of Phragmites communis was also seen here. In the water in front of this 
marshy area the following plants occur, and some of them are also found 
at other parts of the loch : — Scirpus lacustris, Myriophyllum spicatum, 
Nymphsea lutea, Castalia speciosa, Potamogeton pectinatus, P. filiformis, as 
well as its variety alpina, Blytt, the last being extremely plentiful in the 
