THE SPLEENWORTS. 259 



seen flourishing in the midst of towns, seeming, 

 indeed, to love the society of man. But the secret 

 of its preference for buildings of various kinds is 

 its fondness for old mortar. When growing on 

 walls the finest specimens are always those which 

 are found at the top of the walls, just beneath 

 the coping stone or crowning bricks, which serve 

 as a protection for the crown of the Wall-rue. 

 Between the bricks of walls and in the crevices 

 of rocks the little fern inserts its wiry fibrous 

 roots, which suck in the moisture pent by the 

 stony covering, and revel in the combination of 

 old mortar and deposits of leaf- mould formed by 

 dropping leaves. The Wall-rue prefers to grow 

 root-stock, crown, and rootlets, horizontally, a 

 position rendered necessary by the habit of the 

 little plant in growing between the mortar lines 

 of walls. From its tufted crown the tiny fronds 

 shoot out in dense clusters. Stem and leafy part 

 are about equal in length. The tiny branches 

 of the frond are placed alternately on each 

 side of the rachis, each branch being again 

 divided into little diamond-shaped lobes. These 



