A PLANT THAT MELTS ICE 43 



its one great act of flowering, just as the egg-laying 

 rose-aphis uses itself up in its orgy of motherhood. 



Now, this is much the same as the way in which 

 soldanella behaves, except that soldanella continues 

 to flower, spring after spring, for many years to- 

 gether. It does not exhaust itself in a single 

 blossoming. Otherwise, the two plants, though 

 so different in size, behave in much the same 

 general fashion. For agave must necessarily 

 evolve a great deal of heat during its rapid flower- 

 ing period ; but this heat is useless to it, as heat, 

 just as the heat we evolve in running a race is, 

 as such, of no advantage to us. The main differ- 

 ence here is that soldanella has need of the heat 

 and employs it deliberately for its own purposes. 

 In the struggle for existence, every point of 'advan- 

 tage any creature possesses must tell in its favour, 

 and the soldanella has thus been enabled to hold 

 its own bravely in the intermediate belt at the 

 margin of the ice-field. But its limits are narrow. 

 In the open ground it is soon lived down by more 

 hardy kinds, which rise higher into the air ; its 

 range is almost entirely bounded by a narrow belt 

 just where the ice is melting. Above that point it 

 cannot grow ; below it taller enemies soon oust 

 and dispossess it. It utilises its short time between 

 these two impossibilities. 



Strange as it sounds, too, the ice itself acts as a 

 sort of protective blanket or coverlet to the trust- 

 ful soldanella. Only a plant that could pierce the 

 ice could ever have hit upon such a paradoxical 

 mode of warming itself by its own internal com- 



