NATURAL HISTORY OF PLANTS. 33 



from corruption, and in dry weather they impart to it their mois- 

 ture, and they protect the stem and the root from the burning rays 

 of the sun *. 



But the use of mosses is greater still. In them plants and trees 

 will grow as well as in the best garden soil. Gleditsch brought 

 many fruit trees to perfection in mosses alone. Some kinds of 

 mosses grow chiefly in wet and marshy places, as the turf moss 

 (Sphagnum palustre). Stagnant waters and ponds have their sur- 

 faces covered with them, and are afterwards, by the marshy plants 

 that grow there, converted into meadows and fields. According to 

 Tacitus, the whole Hercynian forest was once a marsh, though now, 

 in the places described by him, there are fertile fields and meadows. 

 Aged husbandmen in various districts can remember places where 

 formerly there was nothing but stagnant water, which are now 

 converted into fertile, fields and rich meadows. 



The property of mosses to attract moisture occasions their grow- 

 ing most plentifully in wet places. The tops of mountains are cover, 

 ed with a profusion of them, which draw towards them the mois- 

 ture of the clouds ; the clouds thus attracted, and in which the tops 

 of mountains are almost constantly involved, prevent their being able 

 to retain all the moisture, which therefore sinks into the clefts and 

 crevices, whence it proceeds from all sides to the lowest place, and 

 . at last appears in the- form of a spring. Many small springs unite 

 and form a rivulet, which in its progress swells to the size, of a large 

 stream. Thus to the apparently insignificant mosses, are we indebted 

 almost entirely for the mightiest rivers, and to them moreover do 

 we owe the desiccation of extensive swamps, and the fertility of the 

 most unfruitful soils. 



The object of nature is not only the maintenance of every plant, 

 but the turning to use even the decaying parts of every vegetable and 

 animal production. The smallest space is destined to be the abode 

 either of a plant, or of an animal. The richest and most barren 

 soil, the dry sand, the naked rock, the highest Alps, the deepest 

 morals, the bottom of rivers, of ponds, and of the ocean, nay, the 

 darkest cavities under-ground, such as mines, produce their peculiar 



* Mosses andlichens are prejudicial only to yonag (rees where the bark i s 

 still active ; but mosses, when they are very long, may, by retaining a super- 

 abundance of moisture, be hurtful even ttf grown trees. 

 VOL. V D 



