238 THORODDSEN 



In Iceland all which lies above 500 metres is a complete de- 

 sert; this is also true of great parts of all that lies between 300 

 and 500 metres; at this altitude there are, however, rather ex- 

 tensive bogs covered with Carices and Eriophorum, especially to- 

 wards the west (N. W. of Langjokull). Larger and smaller desert- 

 areas are also found lower down; in some places they extend even 

 to the sea, but in such cases they owe their origin to special cir- 

 cumstances the destructive influence of glacier- rivers, volcanic 

 eruptions or blown sand. In many inhabited districts the greater 

 part of the surface consists of a rocky flat with scanty vegetation; 

 a dense plant-growth such as that found in meadows, bogs and 

 heather-moors covers only a very small part of the entire surface 

 of the island, perhaps not more than 1500 2000 square km. ; but 

 the amount so covered cannot be stated with any certainty. The 

 interior plateau owing to its height above sea-level and its climatic 

 conditions will probably never be of any greater importance, as 

 regards the livelihood of the inhabitants, than it is at the present 

 time. Considerable tracts of the lower-lying parts of the plateau 

 (afrjettir), in spite of the very poor herbage, are used as summer- 

 pastures for the hardy Icelandic sheep which are driven up into 

 the mountains about the end of June and fetched home again in 

 the middle of September. No small percentage, however, of these 

 sheep perishes yearly by venturing too far into grassless wastes, 

 falling into rivers and down clefts, being overcome by snow-storms, 

 becoming a prey to foxes, etc. 



The snow-line and the glaciers form the upper limit of plant- 

 growth ; but from thence down to about 500 metres above sea-level, 

 individual plants usually occur widely separated; there are, there- 

 fore, virtually no habitations on the plateau. As the height of the 

 snow-line in the different parts of the island varies greatly, so similar 

 laws 'govern the occurrence of the habitations, which are closely 

 associated with the plant-growth. The highest snow-line occurs in 

 north-east Iceland, and there the habitations also extend furthest 

 upwards. Three parishes are found on the plateau itself, viz. My- 

 vatnssveit at 300 metres above sea-level, Fjallasveit at 400 500 

 metres, and J6kuldalshei5i at 500530 metres. In the last two 

 the number of the farmsteads and of the people has been subject 

 to very great fluctuations. The inhabitants of these parishes main- 

 tain themselves almost entirely by sheep-rearing. In Myvatnssveit 

 the conditions are however more favourable, as it is situated at a 



