188 
CLASS CKYPTOGAMIA. 
At Fig. 158, a ifi a fern, of the genus ^'s- 
Aspleninm, which bears its fruit on the 
back of the fronds ; at ^ is a moss of the 
genus Hypnum, showing two of its flow- 
ers borne on slender pedicels. At c is a 
genus of the Lichen family. At d is the 
Agaricus, one of the most common of the 
mushrooms. It has been said, that Lin- 
naeus, having arranged all plants which 
would admit of classification, cast the re- 
mainder into a heap together, which he 
called Cryptogamous ; he did not, how- 
ever, rest satisfied in thus throwing them 
together, but subdivided this miscellaneous collection into oi- 
ders ; or we might more properly say that he gave names to 
those divisions already marked out by nature. 
285. Order Filices^ or Ferns. — ^The First Order contains the 
Ferns ; their plume-like leaves are called fronds. The fructi- 
fication consists of one-celled spore-cases (called theooe or spo- 
ra/iigia) which open in various ways and discharge the immerous 
minute spores. The fruit (sporangia), mostly disposed in dot£, 
or lines, grows on the back, summit, or near the base of the 
frond, iig. 159, represents the genus polypodium, with 
sporangia in roundish spots on the back of the frond ; 5, as- 
PLENiUM, in lines nearly parallel, diverging from the center of 
the frond ; blechnum, sporangia in uninterrupted lines run- 
ning parallel to the midrib of the frond on both sides ; pteeis, 
or brake, sporangia forming lines on the edge of the leaf. Some 
ferns bear their fruit in a peculiar appendage, as a spike or pro- 
Orderp marked out by nature.— 285. Ferns— Modes of the fractifioatioa ol feriui= 
