SPITSBERGEN 615 



(pea family), the second family of the world, is not even repre- 

 sented, nor is the Orchidacese. The former is, of course, well 

 represented in this country ; the latter is more characteristic 

 of the Tropics. Another interesting absentee is the Labiatae 

 (which includes the deadnettle, etc.). The order in Spitsbergen 

 with the greatest number of species is the Graminaceae (grass 

 family), while the Caryophyllaceae (pink family) and Cruciferae 

 (wallflower family) follow close behind. The most character- 

 istic family of Spitsbergen, however, is the Saxifragaceae, of 

 which there are twelve species, several of which are extremely 

 common. In Great Britain these saxifrages are nearly all 

 restricted to the summits of Scotch mountains. 



The flora, taken generally, is usually considered with the 

 Arctic European flora. Almost all the Spitsbergen species 

 occur in Arctic Europe, together with a great many other Arctic 

 species. On Bear Island, which is smaller in area than Spits- 

 bergen and more isolated, the flora, as would be expected, is 

 much poorer in species, only about twenty-five to thirty species 

 having been found hitherto. These figures for Spitsbergen and 

 Bear Island are quite in agreement with the laws of chance 

 and the general laws of migration of plants. It also suggests 

 that the plants which are now in Spitsbergen did not come 

 from Europe via Bear Island, but rather by way of Franz 

 Josef Land and Novaya Zemlya. A peculiarity about the 

 flora is the presence in eastern Spitsbergen of several Arctic 

 American plants, which do not occur in the western part of 

 the archipelago. No satisfactory explanation of this has yet 

 been advanced. 



The vegetation of Spitsbergen presents many interesting 

 features and provides several important problems. In con- 

 nection with both of these points, it is the way in which the 

 plants are adapted to the peculiar conditions which is most 

 instructive. The essential points of the climate for the plants 

 are the long, severe winter, with its continuous darkness, 

 allowing of no growth or development, and the very short, 

 warm summer, continually light, when all the processes of the 

 plants' activities are possible. Also the conditions during 

 summer may not be altogether favourable to plant life, es- 

 pecially in rather exposed places. It is, therefore, necessary 

 for the plant to sandwich into the three summer months all the 

 work for which other plants in Great Britain have eight to 

 nine months available. Special developments for this purpose 

 are common and merit careful consideration. They will be 

 dealt with rather more fully than are the other subjects already 

 mentioned. 



Perhaps the first set of adaptations to consider are those 

 against the severity of the climate. Naturally, owing to the 



