Mosses and Peat 



when soaked in water, will be at once refreshed and 

 revived ; the leaves open out and stretch themselves, and 

 the whole plant becomes fresh and vigorous. 



A square yard of the feathery green Hypnum mosses 

 will absorb in one minute fully one pound of water. 

 But its capacity for drinking water is very small when 

 compared with the regular peat moss (Sphagnum). A 

 square yard of Sphagnum, after it has been saturated, 

 will yield by careful drying 10,700 grs. of water.^ 



So that it is clearly impossible for mossy stones or 

 moss-covered rocks to be worn away by rain. When 

 the mossy cushion is saturated, the water simply flows 

 over the top of it without ever reaching the stone. 

 Such moss carpets would seem also to protect the rock 

 against weathering by frost action, at least to some 

 extent, for moss is a bad conductor of heat. 



Moss cushions and moss carpets are very interesting, 

 and have much more importance than one would sup- 

 pose. In some of those found on dry walls, the little 

 stems are closely packed and upright. When one looks 

 down on them with a lens, one sees at once how perfect 

 they are when considered as rain and dust traps. Their 

 reddish brown rhizoids are closely entangled, and full 

 of fine soil with insects' eggs, relicts of insect life, worms, 

 &c., interspersed in it. That soil is good and rich ; it 

 is not peat, and so if the germinating rootlet of a grass 

 manages to grow down to it through the moss cushion, 

 it will branch luxuriantly and a vigorous little grass seed- 

 ling will soon display its green rapidly growing leaves 

 against the beautiful velvety background of the moss. 



This colonisation happens more frequently with the 

 other type of moss cushion in which the moss stems 

 form a successive series of curved feathery branched 

 sprays thrown out from the centre and lying flat upon 

 one another. These Hypnoid cushions are much larger 



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