AND PEAT MOSSES OF SCOTLAND. 367 



union of the British Isles with the Continent. The surface of this new land (over- 

 spread with an undulating and profusely dimpled covering of drift deposits), 

 abounded with lakes and pools. We have some grounds for believing, that at 

 this period the climate was still cold enough to nourish glaciers in the higher 

 valleys of our mountainous regions. Forbes has conjectured,* that at this early 

 date our country may have been in the condition of the " barren grounds" of North 

 America. But be that as it may, there can be little doubt, that at some time, 

 during the latest great extension of the European Continent, the upraised beds of 

 the Irish Sea, the English Channel, and the German Ocean, were included under 

 the folds of that broad mantle of green forest, the relics of which are so con- 

 spicuous in our peat mosses. 



It is certain, that at this time the oak and the Scotch pine were contempo- 

 raneous throughout the greater part of Scotland. In the high-level mosses, the 

 latter occurs most abundantly, while the former predominates in the peat of the 

 lowlands. The pine does not appear to have formed any extensive forests at the 

 lower levels of the country, although its remains have been disinterred from many 

 lowland peat mosses.f Its choice of the more elevated regions was influenced, 

 no doubt, chiefly by atmospheric conditions, but also in no slight degree by the 

 nature of the soil. For underneath some low-level mosses, where oak forms the 

 bulk of the buried timber, occasional large-sized pine trees are, as already 

 remarked, not uncommon ; showing, that where the soil was favourable, the 

 climate offered no great hindrance to their growth. It is in the hilly regions 

 that the pine obtains that light gravelly soil which it prefers. At the lower 

 levels, those drift clays and earths chiefly abound, which at a former period 

 afforded a favourite habitat to the oak. 



Upon the whole, it must be conceded, that north-western Europe possessed 

 at this period a climate more nearly approaching perhaps to that of the wooded 

 regions of Canada, than to the climate which characterises Germany at the 

 present time. The tough resinous wood and thick bark of our bog-pines bear 

 emphatic testimony to the rigour of the seasons that nourished them. The 

 present range of the pine in this country, as contrasted with its former wide dif- 

 fusion, is also very significant. How changed the conditions which at one time 

 permitted the increase of great conifers in the south of England and Ireland, but 

 which now restrict their native growth to a limited area in the north of Scotland ! 



II. Causes of the Destruction of the Ancient Forests. 



Wind. — Some of the more apparent causes of the destruction of our ancient 

 forests may now be considered. It is remarkable, that the trees below peat often 



* Memoirs of Geol. Survey. 



■ Vide Sinclair's Stat. Ace, and the New Stat. Ace. passim, and notices in various county 

 histories, &c. 



VOL. XXIV. PART II. 5 Q 



