14 MOSSES AND LIVERWORTS 



resemble one another in general appearance that 

 it is not always easy, especially in the absence 

 of fruit, to distinguish them. 



Rocks provide camping-ground for numerous 

 members of the moss tribe, though many of these 

 might also be classed among the moisture-loving 

 plants of which I have just been speaking. Any 

 one who has walked much in a mountainous 

 region will often have noticed some small plant 

 growing in a crack or crevice of the rock, where 

 it would seem that it must have no easy task to 

 obtain a bare subsistence. It is for such a life 

 as this that the tiny rock-growing mosses are 

 peculiarly fitted, for, from their very size, they 

 are able to find a lodgment where a more pre- 

 tentious plant could not exist ; and, being chiefly 

 dependent for their means of livelihood on the 

 air and the rain, they can flourish in situations 

 where larger vegetable growth would be an im- 

 possibility. Many of these rock-dwellers, indeed, 

 must be specially adapted to live among dry 

 surroundings, for in the higher mountains, such 

 as those of "Wales or Cumberland, we may notice 

 rocks, constantly exposed to the full blaze of 

 the summer sun, which yet bear on their faces 

 patches which, though more like dead seaweed 

 than living plant, will prove, on examination, to 

 be colonies of moss-plants. These particular 

 members of the moss community seem to have the 

 power of sustaining life for a considerable period 



