ARCTIC VEGETATION 69 
species of Botrychium, the genus to which our 
Moonwort belongs, has also been found at Eng- 
lishman’s Harbour. 
In the winter practically the whole of the ground 
is covered with snow: Mr Porsild describes the 
occurrence of chimney-like holes in the snow 
through which rises warm and damp air smelling 
like a greenhouse. The air temperature may be 
— 30° C., while the temperature of small pools of 
water among the vegetation under the snow may 
be as high as 17°C. The occurrence at English- 
man’s Harbour and at other localities on Disko 
Island of plants characteristic of the more southern 
parts of Greenland is consistent with an Eskimo 
legend, according to which Disko Island once lay 
much farther south. In its original home the 
island was a hindrance to navigation and an 
Eskimo sorcerer towed it behind his kayak to its 
present situation. 
Despite the shortness of the season and the hard 
conditions inseparable from an Arctic climate, the 
vegetation competes successfully, in the show it 
makes, with that of warmer countries and is in 
some respects superior. How, it may be asked, 
does the vegetation of Greenland compare with 
that of the Tropics? Sunlight, air, and water are 
everywhere the driving forces of the living plant. 
In Arctic lands cold and dry winds and winter 
snow set limits to the upward growth of shoots 
and compel them to hug the ground and to exer- 
cise a strict economy in the production of vertical 
stems. A large proportion of the energy available 
