THE PURPLE SAXIFRAGE 85 



snow of the far north. I think not, but the range of plants 

 is generally known long before their structure has been 

 investigated, and it was so in this case. 



Considering how peculiar aie the conditions of life in 

 polar regions, that the surface of the ground is seldom 

 free from ice and snow, that the subsoil is often per- 

 manently frozen, that for months together in winter the 

 sun never rises, while for as many months in summer he 

 never sets, one would have expected to find the arctic 

 plants, or many of them, strikingly different from all 

 others in appearance and internal structure : having 

 become adapted to polar conditions, we might suppose 

 that they would thereby become unfit for all others. Our 

 purple saxifrage shows how mistaken any such expecta- 

 tion would be. It has its special adaptations to arctic 

 life, as we shall shortly see, but these adaptations do not 

 catch the eye at a glance. And I think that no one 

 without direct observation would have ever suspected 

 that among the plants which venture nearest to the north 

 pole are dandelion and lady's smock, which we consider 

 very ordinary plants indeed. 



The conditions of arctic life are not so trying to plants 

 as to animals. When frost sets in and the ground is 

 buried deep in snow, very nearly all plant-life ceases to 

 be active ; on the other hand, when the sun shines 

 throughout the twenty- four hours almost any plant would 

 thrive. The only general physical condition that is 

 rigorously imposed upon arctic plants is the not very 

 stringent one that they must be able to endure intense 

 cold during the dormant season. The success or failure 

 of the many competing species is probably determined by 

 other conditions, such as whether the flowers are attractive 

 to the insects which buzz about the flowers in the arctic 

 summer, or whether the seeds are capable of transport by 

 any natural agent over great expanses of snow. In all 

 climates we find that the qualities which ensure the pre- 

 dominance of certain species are hardly to be appreciated 



