A VEGETABLE PUMP 



There are two kinds of peat-mosses, which, although there 

 are many intermediate types, may be kept apart. 



The first, like the one near Stirling, Lochar and Solway 

 Moss, near Dumfries, and Linwood, near Glasgow, have been 

 formed in low-lying flat estuarine marshes. 



If one refers back to page 210, it will be seen how reeds 

 and rushes and marsh plants may gradually fill up river 

 backwaters. Eventually a saturated, marshy meadow is pro- 

 duced. 



Then comes the chance of that wonderful moss the peat- 

 moss, or Sphagnum. It is scarcely possible to appreciate its 

 structure without the help of a microscope and a good deal 

 of trouble in the way of imagination. 



It is in a small way a sort of vegetable pump which raises 

 water a few inches or so. Stem and leaves and branches 

 possess little cistern cells, which act both as capillary tubes 

 raising the water and also retain it. The stems are upright 

 and develop many branches, so that they become a close- 

 ranked or serried carpet of upright moss-stems squeezed 

 together, which floats on the surface of the water. Each 

 moss-stem is growing upwards and dying off* below. In con- 

 sequence, the bottom gets filled up by dead mossy pieces, 

 which accumulate there, while the live moss-carpet remains 

 floating on the surface of the loathly, black, peaty water. 



In many peat-mosses the water gets entirely filled up, but 

 that does not stop the formation of the peat-moss. It is 

 now resting on the water-saturated remains of its forefathers, 

 and if water is abundantly supplied it goes on developing. 



Thus in these lowland or estuarine peat-mosses the moss 

 eventually occupies the water, and goes on growing. After 

 this it develops like the moorland mosses which cover most 

 of the Lowlands and Highlands of Scotland. They cover the 



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