50 STUDIES IN GAEDENING 



tioned the Aethionemas, some of the more diflBcuIt 

 Campanulas, the Acanthohmons, the Wahlenbergias 

 (also called Edraianthus), Armeria caespitosa, some 

 of the smaller and more delicate Pinks such as Dian- 

 thus neglectus and D. freynii. Geranium argenteum 

 and G. cinereum, Hypericum repens, H. reptans, and 

 H. coris, Iberis saxatilis. Lychnis lagascae, Phyteuma 

 comosum, Potentilla nitida, Saxifraga longifolia, S, 

 pyramidalis, and many other saxifrages of the same 

 class, Silene Elizabethae, Antirrhinum asarina, Ero- 

 dium guttatum, and E. chrysanthum. These plants 

 are not all difficult to grow; a good many of them, in- 

 deed, are quite easy; but they all do best, and are 

 safest against the caprices of our climate, when grown 

 in deep and narrow chinks between rocks; and they 

 will all thrive with very little soil. The problem of 

 the cultivation of plants of this kind is, therefore, 

 fairly simple. The main thing is to induce them to 

 root deeply. Until they have done that, they must 

 be protected from drought as a rule; but, when they 

 have done it, they will protect themselves. Most of 

 them will thrust their roots several feet down. The 

 rocks about them, therefore, should be equally deeply 

 embedded in the ground, and the soil should be thor- 

 oughly well drained as far as their roots are likely 

 to descend. It is no use to attempt to grow such 

 plants upon a heavy or damp subsoil with a foot or 

 so of rocks and grit above it. They will thrive until 

 they reach the subsoil, and then their roots will rot 

 away the first winter after they have reached it. 



