Mosses and Peat 



and may produce nearly an inch of soil. The younger 

 fronds not only overlie and overshade the older branches, 

 but there is a strong suspicion that they hasten their 

 decay by feeding upon them ! One sees plumes of 

 rhizoids {i.e. root-fibres) fixed upon the withering older 

 fronds of the same plant and apparently extracting from 

 them any valuable material that yet exists. 1 



Fungus parasites sometimes occur on moss rhizoids, 

 but it is uncertain if they possess a well-marked fungus 

 assistant or mycorhiza such as one finds with higher 

 plants. The liverworts (allied to the mosses) do some- 

 times possess one. 2 * But the moss family has carried 

 this power of absorbing water to such a degree of per- 

 fection that it often becomes a nuisance to mankind. 



One sees this in the " f og " of ordinary pasture land, 

 which is a smothering moss development which in- 

 terferes with the growth of grasses and other plants. 

 Such fog appears when the land is so wet or has been 

 so much grazed that the flowering plants are not grow- 

 ing rapidly enough to keep the moss in check. (One 

 can almost always find a few mossy strands anywhere 

 even in good pasture and particularly in autumn.) But 

 the peat mosses of lowland swamps and of the moors of 

 Britain and Ireland are even more serious evils, for they 

 occupy, almost uselessly, a large extent of country. 



Such feathery mosses as the Hypnums and Hylo- 

 comiums are apt to weave themselves about the stem 

 bases of marsh plants and mud plants. They absorb 

 and hold water strongly, but in such places, if the ground 

 is always water-saturated, the peat moss, Sphagnum, 

 will soon appear. It is of a pale whitish or yellowish 

 green (often, however, pink-tinged at the tips). The 

 stems are upright and branch at every fourth leaf, so 



* A fungus, Mollisia Jungermanniae, assists and depends upon Calypogeia. 

 Marchantia, Preussia, and Fegatella also have a mycorhiza. 



7 2 



