416 REPORTS ON THE STATE OF SCIENCE, 
determined. The forest zone is absent and Hmpetrum, Hriophorum, and 
Sphagnum appear to be the principal plants. The summit plateau at 
2,930 feet is covered with patches of Rhacomitrium lanuginosum alter- 
nating with bare stony areas. 
The Tyne Basin.—Sections were taken over the great expanse of peat 
on each side of Smittergill Burn, Black Burn, and Cash Burn, forming 
the headwaters of the river 8. Tyne, on the north side of Cross Fell. 
In most places the remains of an arctic or sub-arctic vegetation rest 
upon the drifts : this is covered with a considerable thickness of peat formed 
from Phragmites communis. Above this the birch zone forms a datum 
line over the whole district. The wood varies greatly in size, but is 
seldom less than 8 inches and sometimes attains 18 inches in diameter. 
Where denudation has not been active the forest is overlaid by 7-10 feet 
of recent peat, but in many places the whole of this has wasted away, 
leaving the birch wood scattered over the surface of the peat. The pre- 
sence of Hlatine hexandra in the forest bed in several sections at 2,000- 
2,600 feet both in Teesdale and Tynedale is of interest} as this plant is 
chiefly confined to the western portion of Britain at the present time, and 
is not typical of peat bogs at high elevations. Of similar interest is the 
occurrence of Vibwrnwm opulus in the birch zone from a section at about 
2,330 feet. The presence of these plants implies different conditions from 
those indicated by the underlying Salix reticulata and S. arbuscula. 
The basal arctic vegetation and the forest bed can be regarded as true 
horizons, and as they are present both on the Pennines and in Scotland a 
brief comparison may be made between the two regions :— 
General sequence of Strata in the Sequence of Strata in Teesdale 
Scottish Highlands. and Tynedale. 
1, Recent peat, Scirpus cwspitosus, Spha- Recent peat, Hriophorum, Sphagnum, and 
gnum, and Eriophorum. Calluna. 
2. Pinus sylvestris and Calluna. Betula alba, Alnus glutinosa, Viburnum 
opulus, LElatine hewandra, Lychnis 
diurna, 
3. Sphagnum, Scirpus cespitosus. 
4. Pinus sylvestris and Calluna. 
5. Sphagnum and Eriophorum. Phragmites communis. 
6. Sub-aretic beds, Salix arbuscula, Em- Salix arbuscula, Empetrum. 
petrum, and Potentilla Comarum. 
7. Salix reticulata, S. herbacea, Dryas 
octopetala, Arctostaphylos alpina, 
Salix reticulata, &c. 
Whilst the salient features are the same in both regions (7.¢., an arctic 
bed at the base overlaid by a forest bed) nothing can be more striking 
than the difference in the flora. All the Scottish peat areas, at altitudes 
approaching 2,000 feet, contain the remains of a moorland flora above or 
below the forest zone, but in this district, at nearly 2,700 feet, several feet 
of peat below the forest bed are formed entirely of Phragmites communis. 
The difference is just as marked if we compare the Phragmites zone with 
the present vegetation of Calluna, Vaccinium Myrtillus, Empetrum, Erio- 
phorum, and Rubus Chamemorus. Before the period of the Upper 
Forest, the whole area—even near the summit of Cross Fell—consisted of 
an extensive reed swamp, and in some places this persisted through the 
upper forest period. This was the case on the floors of the valleys and at 
the base of some of the steep escarpments. Several such old swamps or 
shallow lakes have been traced—one on Cross Gill Pants, where the 
drifts appear to form a shallow basin, although this has now been filled 
