264 PLANT LIFE. 



will show all the characteristics that are here mentioned. 

 Some are of very modern origin ; and, unfortunately, in 

 Scotland very few have been scientifically examined. 



When the ice-sheet retreated polewards, the land 

 must have had a very desolate appearance. Perhaps 

 the following quotation from Bernacchi gives a fair idea 

 of the landscape as it would then present itself, though 

 this is taken from the Antarctic Continent. " Gravel 

 and pebbles were heaped up in mounds and ridges. In 

 some places these ridges coalesced so as to enclose 

 basin-shaped hollows. Bleached remains of thousands 

 of penguins were scattered all over the platform, mostly 

 young birds that had succumbed to the severity of the 

 climate." 



" The scene before us looked inexpressibly desolate." 

 " No token of vitality anywhere, nothing to be seen 

 on the steep slopes of the mountains but rock and ice." 

 Upon this exposed ground still subject to a severe 

 arctic climate, first such little Arctic plants as Salix 

 polaris and Betida nana began to grow. In wet low-lying 

 places, there would then develop a marsh flora consist- 

 ing of Rushes and Reeds such as Phraginites and Ranun- 

 culus aquatilis, or of similar swamp or marsh species. 

 If the ground became permanently waterlogged, mosses 

 would soon begin to form upon the remains of these 

 Reeds and other aquatics. Amongst these mosses 

 Sphagnum, the peat moss proper, would soon take a 

 prominent place. The structure and growth of this 

 plant is extremely well adapted to its mode of life, and 

 enables it to choke out almost every other kind of 

 vegetation. The stems are upright, and grow in close- 

 set ranks so that the moss forms a continuous cushion 

 generally saturated with water. The structure both of 

 the stem and leaf is well adapted to retain any water 



