164 
Proceedings of the Royal Society of Edinburgh. [Sess. 
of which it sinks in order to hibernate, whilst the Polygonum grows best 
in comparatively shallow water. (2) Owing to the luxuriant development 
of the floating leaves of the Polygonum, which obstruct the free access of 
light to the water below, the Ceratophyllum is not able to thirve in this 
darkened area, and consequently becomes extinct at the margin of the 
Polygonum association. Notwithstanding its absence in a few small areas, 
the quantity of Ceratophyllum in this loch is extraordinary. Equally 
striking is the flora of the bog at the west end. Considerable portions of 
it are covered with associations of Menyanthes trifoliata, the individuals of 
which are so closely compacted that no other plants can thrive amongst 
them. Ranunculus Lingua is also very abundant and grows in large patches, 
the vivid yellow of its masses of flowers affording an agreeable tone to the 
sombre green of the tussocks of Carex paniculata (fig. 103), which dominates 
the greater portion of the bog. 
Besides those already mentioned, the following plants occur here : — 
Callitriche autumnalis, Potamogeton Zizii, Zannichellia palustris, Ranunculus 
circinatus, Myriophyllum spicatum, Lemna minor, L. trisulca, Cladophora 
crispata, Carex rostrata, Heleocharis palustris, Cicuta virosa, Sparganium 
simplex, S. ramosum, Epilobium hirsutum, Ranunculus Flammula, Caltha 
palustris, Myosotis palustris, Galium palustre, Spiraea Ulmaria, Mentha 
aquatica, Juncus effusus, Phalaris arundinacea, Montia fontana, etc. [Scirpus 
sylvatica, close to the loch. — J. M‘A.]. A number of Bryophytes occur about 
the banks and on fallen timber, particularly at the south and west sides, 
but as these are chiefly forms that grow in damp woods and similar places 
they cannot be named as belonging to the loch. 
Loch Fitty is situated amidst a mining and agricultural district 3 
miles west of Cowdenbeath. It is a mile long by J mile wide, is at an elevation 
of 413 feet above sea level, and has a maximum depth of 17 feet. The water is 
clear but it has a flat, dead appearance, especially so in autumn when the 
abundant vegetation, particularly the Characese, is decomposing. A fine 
tow-net used in the middle of the loch at the end of September caught a 
very pure collection of Asterionella formosa. Many of the submersed 
plants were heavily incrusted with lime, which proves the presence of that 
substance in the water. Some plants, e.g. Potamogeton Zizii and P. 
perfoliatus, were so weighted with this substance that many of them were 
lying on the bottom instead of rising up to the surface. The shore at the 
north side is stony, gravelly or sandy, and almost destitute of marsh plants. 
At the south side a portion of the shore is composed of a bank of shale, 
which has been thrown out from an adjacent mine, and a number of aquatic 
plants occur in the pools and little bays formed by the irregularities in this 
