TREES IN THE LIGNITES. 155 



The upright trunks of trees always indicate the dying-out of 

 the lignite-deposit ; in other parts the trunks lie horizontally. 



With regard to the plants which produced these lignites some 

 information is derived from the remains found partly in the 

 lignite itself and partly in the intercalated clay-beds. They are, 

 for the most part, badly preserved, and it is difficult to de- 

 termine them; but twenty-four species may be recognized. 

 Among these we find eight trees and one shrub. The trees are 

 as follows : 



1. The common fir (Pinus Abies, Linn.). Prof. Heer has 

 obtained fine fir-cones from Diirnten, Wetzikon, Utznach, and 

 Morschweil. Most of them are smaller than the full-grown 

 cones of the living tree ; but there are among them specimens 

 which attain a length of 120 millimetres (or 4' 7 inches), and 

 are therefore not inferior in size to the cones of Swiss firs. The 

 smaller cones are probably not mature, and they have conse- 

 quently only small seeds. The scales of the ripe cones agree 

 in form and size with those of the living tree, as do also the 

 two seeds which lie under each scale, as shown in. fig. 333, a. 

 The scale is traversed by fine longitudinal striae, and narrowed 

 above into a short lobe, which is sometimes emarginate (fig. 

 333, b), sometimes obtusely rounded off (fig. 333, a). The 

 scales are generally somewhat more rounded at the apex than 

 in the Swiss firs ; and in this they agree with the firs of Northern 

 Russia. When fresh and moist the scales usually press against 

 each other ; but in drying they spring asunder, and thus acquire 

 a ragged appearance, which is increased by the partial break- 

 ing of the scales as they become rigid. Besides the cones, Prof. 

 Heer finds at Diirnten trunks, the wood of which agrees in its 

 microscopic characters with that of the common fir; he can 

 therefore hardly doubt that the fir of the lignites belongs to 

 the same species as the common Swiss fir. 



2. Pines, including the common pine (Pinus sylvestris) and 

 the mountain-pine (Pinus montana, Mill.). At Diirnten and 

 Utznach the trunks of pines constitute a considerable portion of 

 the lignites. They must have sunk into the peat-bog ; for they 

 lie crossing each other in various directions. In the fresh and 

 moist state the wood is soft, and may be easily cut with a knife ; 



