1004 - 5 .] 
Flora of Scottish Lakes. 
1003 
phyllum alterniflorum, Glyceria fluitans, Sphagnum acutifolium, 
S. cuspidatum, var. plumosum, Hypnum stramineum, H. trifarium, 
Rhacomitrium aciculare, Scapania undulata, Nardia compressa, 
Batrachospermum moniliforme, Zygnema Yaucherii, Menyanthes 
trifoliata, Comarum palustre, Equisetum limosum, Heleocharis 
palustris, Eriophoruni vaginatum, E. polystachion, Triglochin 
palustre, Juncus effusus, J. articulatus, Caltha palustris, Ranun- 
culus Flammula, Hydrocotyle vulgaris, Carex binervis, C. dioica. 
At Loch nam Faoileag (one of this group) the eastern shore 
presents a very curious appearance. It is almost jet-black, with 
white quartzite rocks protruding here and there (fig. 49). Upon 
examination the apparent black sand was found to consist of 
grains of carbonised vegetable matter looking exactly like coarse 
gunpowder. Microscopical analysis of these grains revealed them 
to be the remains of small woody plants with a close grain, but 
the fragments are too much burnt and too small for exact identi- 
fication. Probably they have been blown into the loch from the 
moor after extensive heather-burning by strong westerly winds. 
I have only seen a substance similar to this at one other loch, 
viz., Coire Glas, in Glen Garry Forest, but there it was brown in 
colour, not black. Fig. 50 illustrates a terrestrial form of P. 
natans found at a peat pool about a mile from Loch nam Faoileag. 
I have also observed them at other places. It is perhaps a state 
reverting towards a terrestrial ancestor, induced by an inadequate 
water supply through the filling up of the pool by the formation 
of sphagnum peat. 
Crossing the picturesque and charming Glen Moriston, through 
which flows a splendid river (fig. 51), we enter a desolate mountain 
region remarkable for the great number of its lochs. These are at 
an elevation of 1000 to 1600 feet. With the exception of dwarf 
birch or mountain ash on the islands of a few of them, their 
shores are treeless, and frequently entirely devoid of vegetation. 
Their waters are without exception peaty, often extremely so. At 
Loch a’ Mheig there is a great development of Carex rostrata, 
encroaching in a semicircular manner over the loch (fig. 52). The 
darker patches in the photograph indicate the Carex rostrata in 1 2 
to 18 inches of water; the lighter patches, right and left of the 
island, with trees, are very shallow water or bog with Menyanthes. 
