Mar. 1899.] BOTANICAL SOCIETY OF EDINBURGH l75 



of Nasturtium officinale, Asplenium Buta-muraria, and 

 Scolopendrium. The only locality in the district for 

 Veronica Beccabunga is on this formation. Ecinunculus 

 sceleratus and Veronica Anayallis are confined to wet 

 places on the shore ; B. hulbosus to pastures adjoining 

 a sand dune ; Buhus corylifoUus is frequent in the 

 neighbouring island of Eigg ; and Listera ovata occurs 

 in Mull and Eigg. 



It is interesting to note that several aquatics which are 

 found in the low-lying islands of the Inner and Outer 

 Hebrides, do not occur on this part of the mainland. 

 These are Batrachian Banunculi, Hijjpuris, Apiiim nodi- 

 jlorum, A. iiiundatum, (Enanthe LachenaHi, Alisma 

 ranunculoides, Potamogeton filiformis, and species of Chara, 

 with the exception of C. fragilis. The flora of the coast 

 north of Loch Linnhe may be charactised as being of three 

 kinds: — (1) That of the basalts and gabbro, which includes 

 part of Morvern and Ardnamurchan, Mull, Eigg, Eum, 

 Canna, and Skye ; (2) The Dalradian schists, to the borders 

 of Eoss-shire ; (3) The Outer Hebrides, with one island in 

 the Inuer Hebrides, e.g. Tiree, the geological formation and 

 physical features of which are those of this group. The 

 island of Coll is of a similar Lewisian gneiss to that of 

 the Outer Hebrides, and its flora has many features in 

 common with it, but it also has much in common with 

 that of the schists. 



As is generally the case in the districts immediately 

 bordering the west coast, the hills descend more or less 

 steeply on most sides to nearly sea-level, so that the 

 valleys are little elevated. This causes an absence of 

 tableland, with the result that there is little soil, except 

 at the bottom of the valleys; also that steep rocks descend 

 to a low altitude. Eor this reason, the altitude at which 

 cultivation can be carried on, and low ground plants 

 ascend, is slight; while Alpine plants can find a favourable 

 site at a low elevation, assisted in this latter case by 

 the suitable moisture of the climate. Cultivation stops at 

 about 400 ft., the fructicose BuU at 500 ft., Pteris a.t an 

 average of 1250 ft. on the south side of the hills, and 

 900 ft. on the north side. The highest limit on the 

 hill sides of copses is about 700 ft. The highest limits 



