160 Proceedings of the Koyal Society of Edinburgh. [Sess. 



however, became enliohtened reofardinof the dansrer of this inc(ic of sewaofe 

 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, particularl}" 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 Algte, 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 Alga3 have 

 considerably diminished, especially the Cladophorse, whilst everything is 

 covered with black filth. The marginal vegetation previousl}^ mentioned is 

 luxui'iant, 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 eflusus, 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 jDropagating 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 



