294 HEATHS AND FERNS. CHAP. xviu. 



"But what ails Dr. Balfour ? I am wearying to 

 hear what these roses are. He need not hesitate to sa} 

 what he thinks. I lay traps for no one. 



" How comes it, that of all the Scotch heaths, Erica 

 Tetralix only should be given to the habit of putting out 

 varieties. I have watched Calluna vulgaris and Erica 

 cinerea, and never yet, among thousands of thousands, 

 found a notable variety. But with Erica Tetralix, the 

 loveliest of the three, the case is very different. It is 

 subject to strange shiftings and changings, and I have 

 some delightful varieties from it. If Erica Tetralix was 

 sent to some Darwinian academy, wonderful results 

 would undoubtedly follow ! 



"Your society doubted whether the variety of the 

 lady fern, known as Athyrium molle, was really native 

 to Caithness. Since I saw you, I have got two speci- 

 mens of the fern from England ; but Dunnet Cliffs pro- 

 duce far finer specimens of the same fern. Take my 

 word for it. I have got two specimens of the variety 

 rhceticum from England ; the same fern is also here. 



" In your catalogue, I observe that you have marked 

 Poa aquatica as a native of Caithness. That is serious. 

 The red Poa does not grow in Caithness." 



" I'll not write to you again for three months. Attend 

 to your studies." 



We have quoted these extracts to show howthoroughly 

 Dick had mastered the botany of Caithness. He wan- 

 dered over the country far and near in spring, summer, 

 autumn, and whiter, and collected all that grew during 

 those seasons. 



