ON PEAT MOSS DEPOSITS. 417 
with peat. Another similar basin has been found in Tynedale, near 
Bulmans Hills, at 2,000 feet. In most places, however, the Phragmites 
disappears at the beginning of the Upper Forest period. 
The flora of the Upper Forest is also very different from the corre- 
sponding zone in the Highlands. 
In Scotland this layer nearly always consists of Pinus sylvestris and 
Calluna, whilst on Cross Fell it contains Betula alba, Alnus glutinosa, 
Elatine hexandra, Viburnum opulus, Ajuga reptans, and Lychnis diurna. 
The last-named plant is very abundant, scores of seeds being obtainable 
from quite small pieces of peat. The abundance of these plants at com- 
paratively high elevations indicates that the climatic conditions during 
their growth were much more genial than during the deposition of the 
Salix reticulata and S. arbuscula of the basal layers of the peat, and affords 
some evidence that the forest periods were temperate in character. The 
stratification of the Upper Forest is different in this area from that in the 
Scottish Highland areas so far investigated. In place of the two zones of 
Pinus sylvestris separated by peat bog and arctic plants characteristic of 
the north of Scotland, we have here only a single birch zone. This 
sequence corresponds with that in the Scottish Southern Uplands. As 
far as the evidence at present available goes, the Upper Forest period 
was interrupted by a change which caused a replacement of pine and 
heather by peat bog and arctic plants. Subsequently the peat areas were 
re-invaded by a pine and heather association. The changes which pro- 
duced this alternation in the flora did not apparently extend further south 
than the north of Scotland, or the Mid-Highlands. The results may be 
briefly summarised as follows :— 
The Caithness-Sutherland area exhibits the same general sequence as 
other areas in the north of Scotland. The arctic plants found between 
the two layers of the upper forest is a feature of some importance. The 
constant alternation of pine forest, Sphagnum and Scirpus peat free from 
tree remains, covered with a second pine forest, seemed to indicate a wide- 
spread climatic change, and the frequent presence in this district of Salia 
arbuscula and S. reticulata in the intervening peat is fairly conclusive. 
The Cross Fell area is of interest, as it shows the same stages as areas in 
the north of Scotland, although the flora is of an entirely different character. 
The presence of such plants as Hlatine hexandra, Ajuga reptans, Viburnum 
opwlus, birch and hazel trees of large size at altitudes of 2,400 feet, points 
to the fact that the upper forest grew under conditions more temperate 
than those of the present day. The basal arctic bed, on the other hand, 
containing Salix reticulata, S. arbuscula, and Arctostaphylos alpina, points 
to a period when the arctic-alpine plants now confined to small areas in 
the north of Scotland had a much more extensive range on the hills in the 
north of England. 
Gotameal Photographs.—Report of the Committee, consisting of Pro- 
fessor F, W. OLIVER (Chairman), Professor F. E. Wess (Secretary), 
Dr. W. G. Smiru, Mr. A. G. Tanstry, Dr. T. W. WoopHEaD, and 
Professor R. H. Yapp, for the Registration of Negatives of Photo- 
graphs of Botanical Interest. (Drawn up by the Secretary.) 
Tue Committee have met twice during the past year, and have made 
arrangements with the British Botanical Survey Committee whereby 
1907. EE 
