ON THE PLANT REMAINS IN THE SCOTTISH PEAT MOSSES. hel 
_ papers dealing with Arctic zones in the late glacial deposits of the Continent, and I hope 
that correlation between these zones and those in the British peat may be possible 
when areas have been investigated in the north of Scotland. 
The general sequence of vegetation observed in the peat of the several districts may 
be summarised as follows :— 
The Merrick and Kells mosses, and the mosses in the Tweedsmuir district, occur 
above and upon the moraines of the local glaciers of the Southern Uplands, and must, 
therefore, be of later date than these. 
That these mosses began to grow at some period between the disappearance of the 
local glaciers and the reappearance of glacial conditions, is shown by the presence in 
both districts of an Arctic plant-bed running between the lower and upper woodland 
bed. The conditions which would favour the growth of such a vegetation in the 8.W. 
of Scotland at only 800-1200 feet, would be severe enough to cause considerable glacia- 
tion in the Highlands. The plant-beds below and above the Arctic bed also tend to 
show that this layer indicates one of the smaller and later returns to glacial conditions ; 
for the beds below show a gradual increase, and above, a gradual decrease, in precipita- 
tion. If this reading is correct, interest would attach to an examination of any deep 
peat deposits resting on the 50-feet raised beach, as we might expect to find, in that 
ease, the representative of the Arctic zone of the Merrick mosses resting upon the surface 
of the beach. 
The peat of the Moorfoots contains no widespread forest beds, basal birch only 
being found low down on some of the hill-sides. Eriophorum and Molinia have been 
found at the base of the peat on the steepest hill-sides, thus showing that these mosses 
began to form under extremely wet conditions, the higher ground being covered with 
Eriophorum bog whilst the lower slopes supported copses of birch and willows. There 
‘is no sign of Arctic vegetation at the base of this peat, but the basal swamp vegetation 
gives place above to a formation indicating much drier and probably colder conditions, 
represented by a zone of Empetrum with Arctostaphylos Uva-ursi. 
The question arises whether this Empetrum bed can be correlated with the Arctic 
zone of the Merrick and Kells mosses and the Tweedsmuir peat. If it is contempo- 
raneous, then the later return to cold conditions represented by the high level corrie 
moraines of the Highlands produced little effect upon the vegetation so far south as the 
Moorfoots, for there are no beds above the Empetrum zone in this peat which show 
any return to cold conditions. 
The lowland mosses of Wigtonshire occupy large hollows. in the till between the 
outcrops of Silurian rocks, and reach a depth of about 20 feet. No Arctic plants have 
been found at the base, the basal vegetation consisting of shrubby birch, which is con- 
tinuous over the area. The beds above this represent lake or swamp conditions; but a 
return to forest conditions took place later, when the mosses became fringed with pine 
trees of large size. The peat above the pine zone is formed of wet-condition moorland 
plants. 
