CLASSIFICATION OF BOGS. 793 



peat-mosses, heath- plants or mountain-pines ; in their place 

 species of Hypiium and sour herbage (Enophorum) appear, 

 which are their chief components, while stunted Scots pines, 

 alders and birches are here-and-there disseminated. High 

 bogs are distinguished readily, even at a distance, by the 

 appearance of the heather and red-tinted Sphagnum, but 

 morasses resemble extensive sour meadows. 



In the Bavarian plateau, morasses have a subsoil of boulders 

 and gravel brought down from the mountains and usually 

 covered by a thin layer of amorphous calcareous marl, termed 

 locally Aim, which forms an impermeable base for the bog. 

 The surface of mor horizontal, and they are more 



frequent in low lands near rivers than in depressions among 

 hills, where high bogs prevail ; they are more extensive than 

 the latter in southern Bavaria. 



3. Ft-iix. 



The fens of the North German plain have much the same 

 appearance as the morasses of the Swabian plateau, as they 

 are also formed of sour herbage, such as rushes, sedges, cotton- 

 sedge (Eriophorum) &n.d moss ; but according to Sprengel, they 

 do not yield actual peat, but a muddy humus which is dredged 

 from them. 



These fens are often of large extent, chiefly near the water- 

 courses, but are much less prevalent in North Germany than 

 the high moors. 



[The fens in East Anglia, when near the low chalk hills of 

 that region, as at Mildenhall, sometimes rest on beds of marl 

 formed of the debris of water-plants (Chara) incrusted with 

 carbonate of lime from the brooks running into them, peat 

 also occurring on the Kimmeridge and Oxford clays. In all 

 these cases, the vegetation resembles that of the fens and 

 morasses of Germany. Professor Seeley states that in East 

 Anglia, at the base of the layers of peat there are embedded 

 forests of Scots pine and yew, separated by marine clays. 

 Tr.] 



Although, as a rule, the different kinds of bog preserve their 

 distinctive character, yet there are many intermediate forms. 



