382 MR J. GEIKIE ON THE BURIED FORESTS 



The peat of the lower grounds attains to a much greater depth, and has less 

 of a denuded and wasted aspect than that of the hilly regions. In many spots, 

 indeed, Sphagnum and other peat-forming mosses seem to thrive well. But 

 wherever the slope of the ground suffices to create a drainage, the peat crumbles 

 away. Even where the peat occupies a hollow or plain, where the drainage must 

 be weak, the decay of the moss has often been observed making rapid progress. 

 There are, perhaps, but few bogs in Scotland which do not exhibit what are 

 known as moss-hags — holes usually filled either with soft black mud or dry peaty 

 mould. These moss-hags are the result of denudation, and increase in width by 

 the gradual mouldering away of the surrounding peat. Sometimes a system 

 of natural drains or gutters connects the different holes; but many of these 

 show no apparent outlet, and the water collected in them escapes, by slowly 

 soaking through the moss, or by creeping outwards between the peat and the 

 soil. 



The peat mosses of Scotland are thus only a wreck of what they have once been. 

 The out-growth of peat has ceased to be general. Here and there mosses continue 

 to increase in sufficient abundance to form that substance ; but this increase, 

 such as it is, is far exceeded by the general rate of decay. The peaty covering 

 is almost everywhere full of holes and winding channels, a sure sign that the 

 bogs have ceased to combat against the denuding powers of rain and frost. Their 

 upper surfaces are no longer overspread with Sphagnum — a hard crust of heath 

 and grasses caps them instead. All this points to a decrease in the humidity of 

 our climate. It would be interesting to ascertain at what time a diminished 

 rain-fall first began to tell upon the growth of peat. Dr Anderson has remarked : 

 " It is well known that mosses, large ones especially, are universally bare on the 

 surface (I mind not trifling exceptions), or covered with a few cows of heather 

 only ; and it is as well known, that they have been in the same bare and unpro- 

 ductive state since the earliest accounts of them have been preserved." But the 

 early accounts to which that author refers do not enable us to form a definite 

 notion of the nature of the surface of our peat mosses in olden times. We can 

 only gather from them that moss-troopers enjoyed a certain immunity from 

 the visits of troublesome strangers who, not knowing the secret paths across 

 the mosses, dared not trust themselves to the treacherous surface. Some of 

 the bogs alluded to were, no doubt, flow-mosses, which are equally impassable 

 at the present day by any body of men, either on foot or horseback. It seems 

 impossible, however, to learn from historical records at what time those peat 

 mosses, which cover over the ancient woods, first received their crust of heath 

 and grass, and then began to break up into hags and channels. We know that 

 the Covenanters of the seventeenth century employed the holes in the mosses 

 as hiding-places. Many traditions to this effect are floating about the moory 

 districts of Carrick ; and the cairns and memorial-stones, marking out the spots 



