344 



MR FRANCIS J. LEWIS 



Immediately below the Sphagnum, in layer (3), is a thin zone composed entirely of 

 Calluna stems, and below that, next to Betula (4), is a layer consisting of Poly trichina 

 stems and leaves. The Betula layer itself is traversed about midway by a layer of 

 silty peat, containing remains of Potentilla Comarum, Nestl. 



Accompanying Plants. 



Salix Arbuscula, L. 



Dominant Plant. 



5. Carices. 5. 



6. Empetrum nigrum, L., 8 ins. 6. 



7. Mossy peat, with silt containing many leaves of 7. 



Salix reticulata, L., 6 ins. 



8. Angular boulders, with the interstices filled with 



angular granitic grit. 



Several sections were made near the one just described, at distances up to 100 

 yards ; all presented the same features, and in all of them the Calluna and Polytrichum 

 layers just above the Betula zone were well shown. 



A fresh series of sections was taken further eastwards, and the sequence of beds was 

 found to be essentially the same as that just described. 



One section, for instance, showed the following strata : — 



Dominant Plant. 



1. Scirpus-Sphagnum, 3 ft. 



2. Pinus sylvestris, L. 



3. Sphagnum. 



4. Pinus sylvestris, L. 



5. Eriophorum. 



6. Betula alba, L. 



7. Empetrum nigrum, L. 



8. Salix Arbuscula, L. 



9. Sand. 

 10. Closely packed stones. 



I. 



2. 

 3. 

 4. 

 5. 



9. 

 10. 



Accompanying Plants. 



Calluna (abundant in the upper layers of Erio- 

 phorum). 



Menyanthes trifoliata, L. 



Eriophorum vaginatum, L. 



Eriophorum, Polytrichum. 



Betula nana, L. (abundant in the upper layers). 



Dryas octopetala, L. 



Potentilla Comarum, Nestl. (abundant in the lower 

 layers). 



These three series of sections, taken at different points, agree closely in general 

 characters, although, as might be expected, there are small differences in the character 

 of the peat at the same horizons in the several sections. 



The earliest vegetation that took possession of the land on the passing away of the 

 glaciers consisted of Arctic willows, such as Salix reticulata and Dryas octopetala, L. ; 

 these were quickly followed by a close growth of other creeping willows, such as Salix 

 Arbuscula, L., mixed with a good deal of Potentilla Comarum, Nestl., and some 

 Empetrum nigrum, L., and Arctostaphylos alpina, Spreng. When the upper part of 

 the Salix bed is reached, Betula nana, L., becomes abundant, mixed with quantities 

 of Empetrum stems and seeds. So abundant is the Empetrum that where the streams 

 have cut down to the base of the peat, the wiry stems can be traced all along the peat- 

 hags, standing out from the sides as a fringe of bleached twigs, — presenting very much 

 the same features as the author recorded from the Merrick Hills peat in Galloway (3). 



The dominance of Dryas octopetala, Salix reticulata, S. Arbuscula, with Betula 



