176 



A TEXT-BOOK OF BOTANY 



antiseptic, and in such bogs there are often found almost 

 perfectly preserved specimens of ancient trees or their parts 

 and sometimes of mired animals. 



Peat is extensively used for fuel, being cut into bricks 

 and allowed to dry. The less decomposed peat is brown, 

 and the more completely decomposed is nearly bjack. It 

 is not formed to any large extent in warm countries, 

 probably on account of the rapid decay of vegetation; but 

 in the cooler parts of the globe it has been formed in very 

 large masses. All through northern Asia and Europe, and 

 in the northern United States and Canada, there are millions 

 of acres of peat; but little use has been made of it yet in the 



United States. Its ex- 

 tensive use in Ireland is 

 well known, but there it 

 is more apt to be called 

 turf than peat. 



102. Life-history of a 

 Moss. The conspicuous 

 part of an ordinary moss 

 plant consists of a more 

 or less erect and usually 

 branching stem bearing 

 numerous delicate leaves 

 (Fig. 170,4). This plant 

 is evidently able to make 

 its own food, and it is 

 anchored to its substra- 

 tum by hair-like rhi- 

 zoids. Its power of vege- 

 tative propagation has 

 been described, but it 

 produces no spores. At 

 certain times, however, there usually appears at the end of 

 the main stem or at the end of a branch a rosette of 



FIG. 170. An ordinary moss plant, showing 

 the leafy stem (A) with its rhizoids, and 

 a rosette (5) containing sex-organs. 



