CHAPTER II. 



NATURE OF MOSSES. 



Mosses are for the most part aerial vegetables, attached by 

 rootlets to the soil or substance on which they grow, and de- 

 riving their nutriment partly from this matrix, but partly 

 ako from the moisture of the surrounding air, or, in aquatic 

 species, from the water in which they are immersed. In 

 dry weather they are often completely dormant, and assume 

 a peculiar contracted, shrivelled appearance, as if they were 

 dead, and very different from their condition in active growth. 

 The first shower however revives them, and the functions of 

 all their parts are as vigorous as ever. 



Some species are strictly aquatic, though very rarely bear- 

 ing fruit when completely immersed. In several cases the 

 base alone is constantly moist, but the upper part of the 

 plant, though exposed to a burning sun, is kept moist by ca- 

 pillarity. If however such species are accidentally dried up, 

 they revive when the soil is again saturated with ,moisture. 

 Others flourish only when exposed pretty constantly to the 

 spray of waterfalls, or when entirely shaded from the sun, in 

 caves, or under the shelter of rocks or in their crevices. Some, 

 as species of the exotic genus Meteorium, hang down in loose 

 locks from the branches of trees, giving the woods a dismal 



