229 ON THE NATURAL HISTORY OF THE SOUTH OF SCOTLAND. 



its lower part, where, however, there i3 little alluvial deposit. The bounding 

 ranges of hills are composed of uniform, rounded, smooth-sloped masses, having 

 an elevation apparently of from 800 to 2,000 feet. These hills are generally 

 green, the Heath upon them being regularly burnt, so that a plentiful crop of 

 Grasses, Carices, and Junci, with numerous pasture plants, and patches of Fern, 

 succeed the coarser vegetation which has been destroyed. Scarcely any rocks, 

 properly so called, are to be seen in its whole course, although in several places 

 there are great accumulations of debris along the slopes, and between some of the 

 hills there are deep cuts or water-courses, the sides of which are almost entirely 

 destitute of vegetation. The rock is everywhere greywacke, which is generally 

 small-grained, more crystalline than aggregated, seldom fragmentary, always in 

 thin strata, which are vertical or highly inclined, and sometimes slaty. The soil 

 consists of rounded and angular fragments of grey-wacke, mixed with a light 

 yellow tenacious clay. It being firm, and the sides of the valley presenting no 

 level space, water does not accumulate on the ground. Very little natural wood 

 is to be seen, even by the margins of the limpid stream, and where it occurs it 

 consists merely of some scattered bushes of Hawthorn, Hasel, Mountain Ash, 

 Alder, and Willow. There is no Broom, and scarcely any Furze — plants which 

 in other districts fonn so conspicuous a portion of vegetation. Towards its 

 tipper part, or head, this valley, like the others, becomes narrower, with higher 

 mountains and steeper slopes, the terminal rills flowing through deep and very 

 inclined grooves, and in some places there are crags of considerable height. 



Leaving Mannor Water at the uppermost farm-steading, and proceeding 

 directly southward, we pass over an elevated moss forming the broad ridge which 

 separates that valley from Megget-dale, and opens upon St.'Mary's Loch. In the 

 •ascent we observe several plants, such as Saxifraga stellaris, S. Jiypnoides, 

 Epilobium alpinum, Cochlearia officinalis, and Lycopodium selago y which give 

 promise of a richer harvest to be reaped on the huge mountain-mass that now 

 presents itself at the distance of a few miles on the southern horizon. On the 

 high grounds, here and elsewhere, we observe extensive and often deep deposits 

 of peat, of which none occur on the gravelly slopes bounding the vallies. Beyond 

 Megget-dale, a deep, narrow glen, bounded by lofty mountains presenting the 

 usual aspect and structure, we pass over an elevated and undulated moor, until 

 we arrive at Birkhill, situated at the upper extremity of Moffat Water. 



Ascending to the summit of the ridge or narrow platform which extends along 

 the north-western side of that valley, and passing over a moor deeply covered 

 with peat, in the lowest stratum of which are abundant remains of the roots of 

 trees, principally Birch, we come upon Loch Skene, a small body of water, about 

 three quarters of a mile in length, beyond which is a precipitous corry similar 

 to those of so frequent occurrence in the granitic portion of the Grampian range. 

 This corry presents the most favourable place for alpine plants, and after examining 



