Summary 



pinnately, the frond is termed a "bipinnate" one, and if 

 the secondary pinnae or pinnules, as they are called, be 

 divided in a similar manner, the term " tripinnate " is 

 applied to the whole frond. Very few British ferns are 

 ever more intricately divided than those which are tri- 

 pinnately cut. 



The following is a short summary of the contents of 

 this chapter : 



1. The favourite habitats of British ferns are wood- 

 lands and shady glens, bogs and marshes, moors and 

 mountains, country lanes, and the crevices of walls and 

 rocks. 



2. Ferns may be recognised as such by the clusters 

 of spore cases borne on the backs or edges of their 

 usually much-divided leaves. 



3. Fern-spores produce prothallia, from which spring 

 new fern-plants. Thus there are two generations in 

 the life of a fern the prothallium, or sexual generation, 

 and the spore-bearing, or asexual generation, which 

 alternate with each other. 



4. Ferns possess roots, stems, and leaves, but the 

 stems of British ferns are never perfectly upright. 



5. Fern-leaves, or fronds, are described as pinnate, 

 bipinnate, tripinnate, pinnatifid, or entire. These 

 terms have reference to the leaf divisions. 



