41 



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 organization became extended, the insufficiency 

 of such means of distinction and arrangement became appa- 

 rent ; 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 

 character of association, his groups of Eerns being formed 

 from the resemblances in the form and position of the 

 clusters of ' seed-vessels/ which we have already mentioned 

 (p. 17), under the name of spore-cases. 



Those who immediately succeeded him did but carry out 

 to greater perfection, in accordance with increasing know- 

 ledge, the same general idea of family relationship, the most 

 important additional characteristic called into requisition 

 being that derived from the presence or absence of a general 



