FERNS AND FERN AEEIES. 
189 
come familiar with the newer system at once, as more in 
accordance with recent discoveries concerning the inter¬ 
relations of the pteridophytes. This system has been 
adopted by Professor E. M. Underwood, in his contribu¬ 
tion to Britton and Brown’s Illustrated Flora, Vol. I. (Sub¬ 
kingdom Pteridophyta, PArns and Fern Allies). The 
Fern Bulletin publishes interesting and valuable papers. 
There are also miscellaneous articles on ferns in the vari¬ 
ous botanical publications. 
Among the characters on which the systematic arrange¬ 
ment of the genera and species in this family is founded, 
one of the most prominent and decisive is that of the tem¬ 
porary covering of the sori, called the “indusium.” In 
the great majority of the members of this family this indu¬ 
sium is present. In only two of our genera is it absent. 
When it is present, it may be a true or a false indusium. 
So it results that in relation to the indusium the family is 
divided into three sections ; 1st, those genera which have 
a special indusium ; 2d, those which have a so-called false 
indusium ; 3d, those which have none. Two of our gen¬ 
era have no indusium, Phegopteris (Beech P A ern) and 
Polypodium, the latter being the type of the family. It is 
to be regretted that there is no good English name for Pol¬ 
ypodium. “Polypody” is, like most literal translations of 
Eatin names, meaningless, and “polypode,” which I no¬ 
tice is used by Bailey in his new “School Botany,” is no 
better. May I venture to suggest the name “Many-footed 
Fern?” This would be a good translation of the scientific 
name, it would express a character of the plant itself, and 
it would be understood by persons who are not familiar 
with Eatin. 
Three of our genera have a false or makeshift indusium. 
They are Adiantum (maiden-hair)., Pteris (common brake) 
and Pellsea (cliff brake). In them there is no special cov¬ 
ering evolved for the protection of the young sori, but the 
