ON THE PLANT REMAINS OF THE SCOTTISH PEAT MOSSES. 819 



year of growth. Near the periphery the rings were exceedingly narrow, there being as 

 many as 5 to 1 mm. of radius. 



The specimen from the uppermost or third layer was sawn off close to the stool, and 

 along a radius of 14f inches showed 340 rings, giving an average of 23 to 24 rings per 

 inch. The broadest ring was 3 mm. wide, laid down during the ninety-eighth year of 

 growth. Near the outside the rings number 6 to 1 mm. 



The specimen from the lowest layer may be considered of normal growth, but in the 

 other two, particularly the second layer, growth has proceeded with extreme slowness- 

 The age of the trees from the two upper layers is remarkable, as the limit of Pinus 

 sylvestris is usually placed at 200 years.* 



In this case we have four distinct layers of trees, the lowest (of birch) resting 

 directly upon the boulder clay. This must be an unusual feature, else surely some of the 

 thirty-seven districts which I have examined in all parts of Scotland would have shown 

 similar features. Each successive tree layer is separated by peat formed of Sphagnum, 

 Eriophorum, and Hypnum. 



In 1907 (12) I described the stratification found in the peat on the Spey-Findhorn 

 watershed, which is less than a mile from the Slochd. The sequence over this 

 watershed, and also on the Findhorn-Nairn watershed a few miles farther north, was 

 briefly as follows : — 



1. Eecent peat, Scirpus csespitosus and Sphagnum sps. 



2. Pinus sylvestris. 



3. Sphagnum sps. 



4. Pinus sylvestris. 



5. Sphagnum sps. 



6. Betula alba (shrubby). 



7. Arctic plants. 



On the lower slopes of the Findhorn-Nairn hills the small birch frequently rests 

 upon the drift precisely as it does at Slochd, the only difference between the two places 

 being that there are three pine layers at the Slochd instead of two as elsewhere in this 

 part of Inverness-shire. 



There is, I think, no doubt that all the layers of pine at the Slochd belong to the 

 Upper Forest. There is no reason that this stratum should always be distinguished by 

 one tier of pine stools, for a forest layer simply marks a time when trees spread very 

 generally over the peat bogs — frequently outside the present range of tree distribution. 

 In a level area or a hollow, such as the spot under consideration, a slight change in the 

 local drainage might easily result in the replacement of forest by peat-bog and peat-bog 



* Measurements given by Kirschner, Loew, Schroter (11) for Pinus sylvestris from Denmark and Northern 

 Finland show a much higher rate of growth than is indicated by the trees from Slochd. The measurements given by 

 the above authors for Pinus montana agree more closely, but I think there can be no doubt that the forest at Slochd 

 consists of Pinus sylvestris, for although no cones were found, forest beds of similar trees in other parts of Scotland 

 yield cones which invariably belong to Pinus sylvestris. 



