

The Peat 49 



higher layers of damp-loving land plants are very well exposed 

 and are exceptionally free from silt. Experience there has 

 shown that if peat is only removed down to water level it at 

 once begins to grow again and grows at the rate of a foot in 

 twenty years. 



In Waterbeach Fen and in the West Fen, near Ely, Turf is 

 occasionally dug, and there among the water-loving land 

 plants, stumps, trunks and branches of forest trees are 

 frequent, and a definite succession of oak and yew, fir, and 

 alder and willow forests has been made out. 



About Bottisham, Soham, and in many other parts of the 

 Fens, CJiara is very abundant in the lower part of the peat, and 

 with remains of molluscan shells provides material for the 

 so-called marls which frequently occur. 



The fauna of the peat is much the same as the present 

 fauna of England and nearly all its species are still living. 

 All the mollusca are still living in Cambridgeshire. Of 

 mammals, the only truly extinct species is the great Urus 

 (Bos primigeniw\ but the Roman ox (Bos longifrons) has not 

 been seen wild since Roman times. In the peat it is more 

 abundant than any other vertebrate. A head of Rhinoceros, a 

 species which is extinct in Europe, was recently found in peaty 

 silt at Little Downham, near Ely, but may be derived from 

 older gravel. The beaver, wolf, brown bear (Ursus arctos), 

 and wild boar are now extinct in England but are fairly 

 common in the peat, and with them occur such modern 

 species as the fox, the otter, the marten, the weasel. Among 

 birds the occurrence of the pelican is noteworthy. 



The Fen Alluvium and Marine Silt are only exposed in 

 dyke-making, so are but rarely seen. Only included organisms 

 distinguish the fresh-water from the marine deposits, and 

 both are indiscriminately termed 'Buttery Clay' or 'Warp.' 

 They are dark clays, often very carbonaceous and unctuous 

 to the feel. The fossils show that fresh-water and marine 

 conditions have alternated considerably in most of the districts, 



M. & s. 4 



