( i% ) 
are very llender while young, but become 
much thicker as the feeds ripen. It's fructi- 
fication merits examination, as indeed does 
that of the catkin tribe in general. 
It is necelTary for the pupil to obtain fome 
idea of the ftructure of the Cryptogamia 
plants ; he Ihould therefore begin with the 
ferns (filices). The plants contained in the 
clafs Cryptogamia have not yet been obferved 
to bear either ftamens or piftils ; therefore, 
when the term fructification is applied to 
them, it has no farther fignification than the 
feed, and the apparatus by which that is 
contained and difperfed. The whole tribe 
of the filices, or ferns, is divided into three 
fections, from the manner in which their 
fructifications are difpofed. The firft divifion 
confifts of fuch as have their fruit in fpikes ; 
the fecond, of thofe w 7 hich have it placed on 
the under fide of their leaves ; and the third, 
of what is termed by Linneus radical fructi-* 
fication ; a fpecimen of which is well feen in 
the pepper grafs (pilularia). The botanical 
world is much indebted to the accurate re- 
fear ches of the celebrated Hedwig for many 
important difcoveries in the obfcure families 
of plants belonging to Cryptogamia. Of the 
M % fpiked 
