46 



THE CLASSIFICATION OF FERNS. 



The first notions of classifying the Ferns, if we may 

 judge from tlie 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, tlie 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 tlie 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, 



