378 MR J. GEIKIE ON THE BURIED FORESTS 



ancient forests. It is remarkable, however, that this kind of peaty matter is in 

 general so much decomposed that frequently merely the roots of the old trees can 

 be detected. Leaves, twigs, branches, and trunks have usually mouldered away ; 

 it is chiefly in its upper portions that this stratified peat yields such remains. 

 And their preservation is due to the protecting properties of the overlying true 

 moss peat. It may be doubted, therefore, whether this vegetable mould has in 

 itself any antiseptic qualities. When trees are overturned in a forest, it usually 

 happens that the portions next the soil are the first to decay. Dr Walker has 

 described* the destruction of Drumlanrig Wood in the year 1756. The over- 

 turned trees, he tells us, being allowed to rot on the ground, ripened into what 

 he has termed " peat-earth." The same author has given an account of the moss 

 of Strathcluony,f as showing distinctly, first, at the bottom, roots of fir fixed 

 in a subsoil. Above these came three feet of " peat," then another set of fir 

 roots, covered over by yet other three or four feet of " moss." Again, atop of 

 " these last roots, which were situated three or four feet deep in the moss, an 

 aged fir was growing on the surface." By peat and moss Dr Walker gives us to 

 understand that he means the vegetable mould resulting from the growth and 

 decay of the trunks and branches. These, it would seem, had entirely decom- 

 posed. 



With regard to the chilling effect of this vegetable mould upon growing trees, 

 it may be questioned whether it is likely to produce the effects which Dr Renxie 

 attributes to it. In the American forests it often attains a considerable thickness, 

 yet the trees of those regions show no signs of decay in consequence. Moreover, 

 the succession of fir stumps with intervening peaty matter, at Strathcluony and 

 other places, shows that the mould could not have the destructive effect supposed. 

 For if it had brought about the death of the first tier of trees, it would not surely 

 permit the growth of a second, and even of a third, generation. 



The peat which encloses the fallen trunks of our bogs will be found, when 

 carefully examined, to show fibres of moss, and sometimes to resemble closely the 

 overlying true moss peat. In its upper portions it is certainly not always a heap 

 of decaying leaves and ligneous matter. We must not forget that the weight of 

 a large tree would crush down the few feet of soft pulpy moss on which the trunk 

 fell. Twigs and branches would soon crumble away, and the mould resulting 

 from the partial waste of the stem itself would mingle with the surrounding peat 

 moss ; so that it might well appear, when the tree came to be dug up, as if the 

 peaty matter on which it rested, and by which it was partially enveloped, were 

 composed of its own decomposed substance, differing, as in some degree it must, 

 from the overlying pure mossy peat. 



* Essay on Peat, Highland Society's Prize Essays, toI. ii. p. 19 (Old Series). 

 \ Idem, p. 20. Vide also, for examples of the same phenomena, Irish Bog Reports, vol. ii. 

 p. 61 ; Transactions of the Geological Society (Second Series), vol. ii. p. 140. 



