Cultivation of Rock Ferns. 
23 
Roly podium Robertianum, the limestone polypody, 
requires a dry position, and a mixture of sandy loam 
and chalk. 
Woodsia ilvensis , the oblong Woodsia, must have 
shade and shelter: and the most perfect drainage. 
Make a little hollow of broken bricks, or other porous 
substances. Fill with a mixture of yellow loam and 
silver sand. In this the plant will luxuriate. 
GROUP OP SCOLOPENDEIUMS ON ROCK-WOES, 
