264 EUROPE 



shelters a small number of tiny and tender annuals 

 which accomplish their life-cycle, from seed to seed, in 

 the space of a few weeks. 



Rock, rubble, and parched clay floors in exposed 

 situations, destitute of snow in winter, offer the scantiest 

 vegetation. It may be a coat of crust-lichens or a sparse 

 dotting of pigmy undershrubs and perennial herbs ; often, 

 however, the ground is left bare. These ultimate ex- 

 pressions of plant-life under most unfavourable circum- 

 stances penetrate farthest north and are the pioneers of 

 the higher plant- world. 



Vast carpets of shrubby lichens, interspersed with 

 crawling junipers, dwarf berry-bushes, and other creep- 

 ing under-shrubs ; in comparatively quiet and sheltered 

 surroundings even low shrub-heaths ; marshes of reeds, 

 rushes, sedges, cotton-grass and coarse grass growing on 

 the silt of the margins of the streams ; beautiful oases or 

 bloom-mats on the southern slopes of hillocks at right 

 angles to the rays of the low sun, all aglow with gor- 

 geous flowers ; these form the more luxuriant aspects of 

 the tundra. 



The European tundra is characterized by an abundant 

 development of moss-heaths or moss-swamps, dreary 

 moors formed by vast accumulations of half-decomposed 

 peat-moss remains in the shape of gigantic, spongy, 

 rounded cushions and mounds, sometimes from 10 to 18 

 feet high, with a labyrinth of intervening puddles or 

 gutters, choked with snow in winter and submerged in 

 summer. Mosses are particularly fitted to withstand the 

 dry conditions obtaining on these peat hillocks on account 

 of their capacity of drying up and reviving again rapidly 

 under moisture, and of their hardy nature. The nearest 

 approximation we have to moss-tundras is the peat-bog, 

 common in Ireland and Scotland ; but the formation of 



