jfune /^, 1874] 



NATURE 



91 



the rocks at the upper part of Glen Dole, where Astra- 

 galus a/pi mis grows. These rocks are very rich in plants ; 

 they consist of remarkably twisted and contorted gneiss, 

 specimens of which were collected, The vegetation of 

 the glen was in an advanced state, and some plants were 

 gathered in flower which rarely blossom so early. Among 

 them may be mentioned — Arciostaphylos iiva-iirs?, Vac- 

 ciiiiiiin i'itis-id(ra, Anemone ncmoi'osa, Saxifraga opposi- 

 ti/fllia, forming large pink patches on the rocks ; Liiziila 

 catnpi-stn's, Eiiipctiiim nigrum, Enophorum vagiiiatum, 

 and Cardaini>u- liirsuta. Among the other plants noticed 

 in flower in the glen at Clova were : UIcx curcpcea, Saroih- 

 ainnus scoparius, Gcnis/a anglica, Pruuus aviiait, and 

 Ranunculus Jicaria. Among the plants not in flower 

 which attracted notice were : Silcne acaidis, Saxifraga 

 hypnoidcs and aizoides, Draba incana, Pyrola media, 

 rolundi/olia, secunda, Oxytia rcnifonnis, Gnaphalium 

 supinum, Dryas octopetala. The following ferns were also 

 gathered : Laslrcea oreopteris, Athyrium filix-facmina, 

 rolystichuin lonclulis, P. aculealuin. Poly podium alpestre, 

 P. vulgare, .-Isplenium viride, A. trichomancs, Botry- 

 chium lunaria, and Allosorus crispus. All the species of 

 British Lycopods except inundatuin were gathered. Mr. 

 W. B. Boyd collected some good mosses, including Tri- 

 chosiomum glanccsccns, confined to the rock in Glen Fee 

 on which Oxytropis campeslris grows. It occurred in 

 considerable abundance and in fruit. 



On Saturday 25 the party again went to Acharne, and 

 thence up Glen Esk to Bachnagairn, and by Loch Esk to 

 the White Water and Little Gilrannoch. Again the day 

 was all that could be desired. The snow near the sum- 

 mits of the hills was very refreshing, and on one we had 

 a sufficient extent of snow to give us the benefit of a glis- 

 sade with our poles. This day the botanists and geolo- 

 gists kept together. We specially examined Little 

 Gilrannoch, one of the rocky summits which is interesting 

 as yielding the Lychnis alpina, one of our rarest Alpine 

 plants, and associated with it dwarf specimens of ^•i^;//(v/<i 

 manlinui and Coclilcaria officinalis, the Alpine variety, 

 and Liizula spicata. The rocks were specially examined 

 by the geologists. 



On Monday 27 the botanists examined Loch Brandy 

 and Loch Wharral, and the rocks around them. We 

 noticed particularly the vast crevasse formed at the top 

 of the Snubb by the separation of a great mass of rock, 

 which is gradually giving way, and will ultimately be pre- 

 cipitated into Loch Brandy. Saxifraga oppositifolia was 

 seen as formerly in fine flower. Azalea procundtens was 

 also gathered. In Loch Brandy Isoctcs lacusins and 

 Lobelia dotlinaiina were met with. In ascending the 

 mountains this day we saw a fine effect produced by the 

 thick white mist resting in the valley, while we were on 

 the mountain above it enjoying clear sunshine. Among 

 the mosses collected by Mr. Boyd during the trip may be 

 noticed — Criniinia unicolor, G. doniiiana, Leucodon mo- 

 icnsis, Andtaa campeslris, and Hypnuin catennlaium. 



2. Geological Notes by Prof. Geilcie. — The main ob- 

 ject of the geologists of the excursion was to observe 

 some of the phenomena of the metamorphism of the 

 district, to note the more prominent minerals, to 

 trace the remains of old glaciers, and to connect 

 the general structure of the rocks with the forms of 

 hill, valley, crag, and ravine into which they have been 

 carved. Incidentally, however, they took part in some 

 of the botanical work, their attention being specially 

 directed to the Alpine flora and to the circumstances 

 under which some of the rarer Alpine plants occur. There 

 can be no doubt that, as pointed out by Edward Forbes, 

 our Alpine flora is descended from that which was general 

 over these islands during what is known as the last Ice 

 age. It has been supplanted in the lower districts by the 

 vegetation which has come in with a milder climate ; and 

 it survives on the bleak and cold mountain ridges only so 

 long as it can find its congenial temperature there, or so 



long as the chills and mists of these high regions forbid 

 the further ascent of the plants which, swarming over the 

 country, have driven these northern forms step by step 

 up into these high grounds. It is well-known that the 

 Alpine flora is richer in individuals and in species in 

 the eastern Grampians than anywhere else in Britain. A 

 number of plants are found in no other part of the country, 

 and even in that district several are restricted to mere 

 isolated rocks in some glen or some bare mountain brow. 

 The question proposed to the consideration of the geolo- 

 gists was whether any geological reason could be given 

 for this remarkable distribution, and particularly whether 

 or not the nature of the rocks had had anything to do with 

 it. 



Some attention was accordingly paid to the habitat of 

 three of the rarer and more local species. The Astra- 

 galus alpinus was observed on hard quartzose schist, high 

 up in Glen Dole ; the crag on which the Oxytropis cam- 

 peslris flourishes is a mass of singularly twisted and 

 gnarled quartzose gneiss, with hard siliceous ribs projecting 

 from its surface and showing the crumpled nature of the rock. 

 But in neither of these cases does the rock apparently 

 differ from many other crags in the neighbourhood, where 

 the peculiar plants nevertheless are not found. In the case 

 of the Lychnis alpina a special case seemed at first to be 

 made out in favour of a relation, or at least a coincidence 

 of a local plant with a local rock ; for the locality noted 

 as the habitat of this rare plant was found to present 

 shattered knobs of serpentine projecting through the turf, 

 and on these knobs the Lychnis grows, together with the 

 Cochlearia officinalis and the Armeria maiitima. This 

 rock was not observed by the party in situ in any other 

 part of the district examined. I5efore it was quitted, how- 

 ever, one of the botanists, who strayed farther over the 

 mountain, returned with a piece of mica-schist, as the 

 rock on which the same plants were found growing only 

 a short distance away. It appeared, therefore, probable 

 that, at the most, difference of rock can have had but a 

 very slight influence in the survival and present distribu- 

 tion of the Alpine flora. 



A much more effective influence may be traced to the 

 general physical geography of the country, and especially 

 of the eastern as contrasted with the western districts. 

 The richness of the Aberdeenshire and Forfarshire moun- 

 tains in Alpine plants, as contrasted with those of 

 equal elevation in Invernesshire and Argyllshire, has 

 long been a familiar fact to botanists. The cause 

 of this contrast seems referable not to any diflerence 

 in rock and soil, nor to mere differences in height ; 

 it appears to be explicable by the much greater breadth 

 of high ground in the east than in the west. Every- 

 one who has ascended some of the Grampian ridges re- 

 members the wide undulating moors which spread 

 out before him at', heights of 2,000 or 3,000 ft. The sum- 

 mits are not peaks, so much as huge swells or mounds 

 rising higher than the rest of the vast tableland. In 

 the western counties, however, tlit- craggy mountains 

 tower often into sharp ridges. They are deeply trenched 

 by glens and arms of the sea, so that relatively a smaller 

 area of land rises out of the ordinary lowland vegetation 

 into the chiller regions above. Add to this that the In- 

 vernesshire and Argyllshire hills lie nearer to the 

 warm winds and currents of the Atlantic, and that the 

 Grampian uplands receive the prevalent south-westerly 

 winds after they have been chilled by passing over many 

 leagues of high cold mountain ground. It is in these 

 eastern parts of the Highlands that snow lingers longest, 

 widest, and deepest— a good index, indeed, of the greater 

 severity of the climate. These facts are suggested as 

 afiording some explanation of the comparative abundance 

 of the Alpine flora in that part of Scotland. 



Why in that limited district certain plants should be 

 restricted to mere isolated rocks is a question to which 

 no intelligible and satisfactory answer can at present be 



