( 100 ) 
Cryptogamia, or clandeftine marriage, the 
grand defideratum of botany, as the plants of 
which it confifls have their fructification fo 
obfcure, that there are but few genera in 
which it has yet been diftinc~tly feen. This 
clafs includes all thofe plants, which have a 
ftruclure different from thofe comprifed in 
the other three and twenty claffes, and is 
divided by Linneus into four orders, the 
Alices, ferns ; mufci, moffes ; algae, wrack, 
or feed-weed; fungi, fungufes. The little 
knowledge, that has hitherto been obtained 
of thefe numerous tribes of plants, has been 
confidered a great reproach to the fcience 
of botany. Perhaps the fyflem of Linneus 
may have retarded a more diftinct arrange- 
ment of them, that being founded upon the 
parts of fructification, which in mod of the 
genera belonging to the clafs Cryptogamia 
are fo difficult to afcertain. The ferns are 
defined to be plants bearing their flowers and 
fruit on the back of the leaf or ftalk, which 
in this tribe of plants are the fame, the ftem 
not being diflinguifhable from the common 
foot-ftalk, or rather mid- rib of the leaf : fo 
that, in ftridt propriety, the ferns may be faid 
to be without ftems. The ftem and leaf thus 
united 
