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 black. 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- 
Fic. 170.—An ordinary moss plant, showing tative propagation has 
the leafy stem (.1) with its rhizoids, and been described, but it 
a rosette (B) containing sex-organs. : 
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 
