54 '^^^^ Scottish Xaturalist. 



much so indeed that it is scarcely possible to distinguish at sight whethei* 

 any particular specimen is Norwegian or Scottish. This fact surprised 

 me more particularly with reference to samples of Dicrantun arcticum^ 

 Tvnmia norvegica^ and the alpine states of Didymodon rubellns and 

 Grimmia apocarpa. I leave the reader .'s imagination to \Yeave a theory, 

 slender, yet I think tenable, as to the disposition of the surface of the 

 earth in Northern Europe previous to the glacial epoch. My present 

 limits will not permit me to enlarge further in this direction, although 

 much more might be said on certain curious yet close affinities between the 

 vegetation of distant regions of Northern Europe. 



Peculiarities of Plant Distribution in the West of Scot} and. 



** What strikes a stranger most on our western mountains is the unusual 

 prevalence, and, accordingly, luxuriance of species of the genus Campy- 

 lopus. Within a circle of a radius of 5 or 6 miles from Ben Voirlich by 

 Loch Lomond all the Scotch Canipylopi, with one or two exceptions, may 

 be found, and much the larger proportion of -species of the nearly allied 

 genera Di/:raniwi and Dicranodontium. These mosses give, indeed, a 

 peculiar aspct to the vegetation of these mountains, and they were, besides, 

 the first to give a stimulus to the study of Bryology in the West. In a short 

 period no fewer than six additions in these genera were made to the British 

 Moss Flora. Now reckoning Ben Voirlich as the centre of spread, it is 

 noticeable that in a western direction the prevalence and luxuriance are in- 

 creased, while the number of species is diminished, until on or near the 

 sea-board the eye is attracted and ultimately wearied by extended patches 

 consisting almost entirely of C. longipihis. In the western Islands C. densus 

 is the prevailing species, where it is found in extended masses fruiting free- 

 ly, while in the Outer Hebrides is found the largest and most luxui-ious 

 species of all, C. S/2a7vii. In an easterly direction, on the other hand, the 

 Cajnpylopi degenerate and thin off, while the number of species is varied 

 by the occasional intrusion of C. brcvipiln%, as near Tyndrum, a moss which, 

 according to my experience, may be said to have its centre of spi-ead 

 in Ross-shire in the neighbourhood of Auchnault and Loch Maree. On 

 Ben Lawers, still further east, there is scarcely a Campy/opus to be 

 seen, with the exception of C. torfacens sparingly on the sides of di-ains 

 near the base, while C. coDipactus is confined to one or two spots in 

 the western ravine already alluded to. Near the east coast these mosses 

 again appear in somewhat greater profusion, but not nearly to the same 

 extent as on the west. 



"2d. Sphagna, although common everywhere in uncultivated, and more 

 especially boggy or marshy ground, whether Highland or Lowland, are to 

 be met with in greater profusion in our western glens and on the sides 

 of the mountains than anywhere else, and not only so, but the diversity of 

 species and even of forms is more manifest, so far as my experience 

 goes. 



" 3d. Near Bowling on the Clyde is a prominent rock called Drumbuck, 

 partly basaltic, partly amorphous, and bordered at no great distance by 

 the Old Red Sandstone, on which is found a crowd of mosses of the genus 

 Grimviia. No fewer than eleven species have been detected within an 

 area of a dozen yards, and amongst these, are the rare and beautiful 



