XV. 

 THE BRACKEN FERN (Pleris aquilina). 



THE conspicuous parts of this plant are the large green 

 leaves, or fronds, which rise above the ground, sometimes 

 to the height of five or six feet, and consist of a stem-like 

 axis or rachis^ from which transversely disposed offshoots 

 proceed, these ultimately subdividing into flattened leaflets, 

 \hepinnules. The rachis of each frond may be followed for 

 some distance into the ground. Its imbedded portion ac- 

 quires a brown colour, and eventually passes into an irre- 

 gularly branched body, also of a dark-brown colour, which 

 is commonly called the root of the fern, but is, in reality, a 

 creeping underground stem, or rhizome. From the surface 

 of this, numerous filamentous true roots are given off. 

 Traced in one direction from the attachment of the frond, 

 the rhizome exhibits the withered bases of fronds, developed 

 in former years, which have died down; while, in the 

 opposite direction, it ends, sooner or later, by a rounded 

 extremity beset with numerous fine hairs, which is the apex, 

 or growing extremity, of the stem. Between the free end 

 and the fully formed frond one or more processes, the rudi- 

 ments of fronds, which will attain their full development in 

 following years, are usually found. 



The stem branches in two ways; ist by apparent dicho- 

 tomy of the terminal growing point, and 2nd by the forma- 



