46 
THE CLASSIFICATION OF FERNS. 
The first notions of classifying the Ferns, if we may 
judge from the Latin sentences which served as names 
for them in former times, were derived chiefly from the 
size, form, and general resemblance of the fronds, and the 
situations in which they grew. 
As, however, the knowledge of their structure and orga- 
nization became extended, the insufficiency of such means 
of distinction and arrangement became apparent ; and 
when the great Swedish botanist, Linnaeus, set about the 
task of distributing the plants known to him into family 
groups, he selected the fructification as the leading charac- 
ter of association, his groups of Ferns being formed from 
the resemblances in the form and position of the clusters 
of seed-vessels,"" which we have already mentioned under 
the names of sori and spore-cases. 
Those who immediately succeeded him did but carry 
out to greater perfection, in accordance with increasing 
knowledge, the same general idea of family relationship, 
