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LETTER XXXV. 
/^RYPTOGAMIA, from xgwrro? occuhus 
\^_jl and yupos nuptt&, you know is the 
twenty-fourth Clafs in the Linnaean Syftem. 
You alfo know that it is fo denominated 
becaufe the modus propagandi is concealed, 
either from minutenefs, or within the fruit : 
in the language of Linnaeus, nuptia clam 
celebrantur. The Orders are four, viz. F/- 
Itces, Mufti, Algety Fungi. 
FILICES. This Order comprehends the 
plants commonly known by the name of 
Ferns, whofe fructification is on the back- 
fide of the frondeSy or leaves. The genera 
which have been difcovered in this king- 
dom are, 
Equifetum, Horfe-tail. The plants of this 
genus bear no refemblance to Ferns: 
they are fhaped rather like little Pines, 
from one to three feet high. They 
elevate their fructification on the top 
of a naked fpike proceeding from the 
root. The ftem and leaves are com- 
pofed of tubes inferted into each other 
at 
