ON THE PLANT REMAINS IN THE SCOTTISH PEAT MOSSES. 715 
same way as GUNNAR ANDERSSON found in the Swedish peat. After the pine zone had 
flourishk®d for some time, its place was taken by swamp plants showing much wetter 
conditions ; for the peat above the pine zone is almost wholly formed from the remains 
of Sphagnum, Scirpus sp., and Hriophorum vaginatum. 
I found no evidence of Arctic plants.at the base of these mosses, the first recognisable 
remains above the till being birch and Calluna. The thin seam of peat generally 
underlying this layer contains no recognisable plant remains. It would seem, then, that 
these mosses did not originate until genial conditions had replaced the cold under which 
the till was deposited, and the frequent presence of sand in the first few inches of peat 
suggests that the basal layers are wash peat deposited when the hollows in the till were 
partly under running water. 
Here, as in the previously described districts, there are two woodland beds present, 
separated by peat showing very wet conditions, but, unlike the peat in Galloway and 
Tweedsmuir, there is no layer between the woodland beds of a distinctly Arctic type. It 
is not unreasonable to suppose, however, that the conditions which would favour the 
_ growth of Arctic plants on well-drained mountain valley peat at an altitude of 
800-1200 feet might not produce the same results on wet peat lying at only 200 feet 
and close to the southern coast. If the basal birch in these mosses is contemporaneous 
with the basal birch in Galloway and Tweedsmuir, then the whole of the intervening 
beds in those districts are represented by the Equisetum and Phragmites peat here. 
If the record contained in these mosses was complete, it should carry the story of 
moorland history a stage further back, as the ground has not been glaciated since the 
second mer de glace, the district ice-sheets and valley glaciers not having encroached 
so far upon the low ground away from the hills. 
Lochar Moss (one inch Ordnance Survey—sheets 10 and 6) is the largest tract of 
peat in the south of Scotland, and is situated to the 8.E. of Dumfries. The southern 
part of the moss lies on the 25-feet raised beach, whilst the northern portion lies at 
about 45 feet. A complete investigation of this moss had to be postponed, owing to 
want of time; but some borings made near Racks, at 40 feet above Ordnance datum, 
showed the peat to be 15 feet in depth. The sections al] filled with water before the 
base of the moss was reached, but the borings showed a well-marked basal layer of 
birch embedded in dry black peat, overlaid by 12 feet of Scirpus, Sphagnum, and 
Calluna peat. The peat immediately overlying the birch zone is almost entirely 
formed of Sphagnum, but there is a gradual increase in the amount of Calluna towards 
the surface of the peat. ‘The chief point of interest is the presence of the basal birch 
layer, thus agreeing with the mosses previously described in Wigtonshire as well as 
with the 25-feet raised beach mosses of Cree and Priestside Flow. 
THe Buriep Prat oF THE Earn VALLEY. 
(One inch Ordnance Survey—sheet 48.)—An apparently continuous bed of 
peat underlies the Carse clays of the Earn and Tay valleys. Numerous exposures 
TRANS. ROY. SOC. EDIN., VOL. XLI. PART III. (NO. 28). 106 
