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 
