56 THE REALM OF ORGANISMS CONTRASTED 



We see life persistent and intrusive — spreading everywhere, 

 insinuating itself, adapting itself, resisting everything, 

 defying everything, surviving everything ! 



The great Sequoia trees may be taken as emblems of life's 

 tenacity. For they have been known to flourish over two 

 thousand years. One of the oldest had 2,425 annual rings 

 when it was killed, and must have begun to live 525 years 

 before the Christian era. " We have," wrote Prof. W. R. 

 Dudley, " deep in their annual rings, records which extend 

 far beyond the beginnings of Anglo-Saxon peoples, beyond 

 even the earliest struggles for liberty and democracy among 

 the Greeks — records of forest conflagrations, of the vicis- 

 situdes of the seasons, of periods of drought and periods of 

 abundant and favouring rains." In our conception of life 

 we must not forget these sublime instances of its power 

 to endure. 



§ 5. Struggle and Sifting. 



By the insurgence of life we mean a certain quality of 

 ' push ' or aggressiveness often observable both in plants and 

 animals. It is an outcome of a native self-assertiveness, and 

 it is a factor in the struggle for existence as much as a con- 

 sequence of it. More metaphorically, it is an expression of 

 the ^ will to live ', or of the spirit of adventure. To the 

 conception of the struggle for existence we shall have to 

 give careful consideration at a later stage ; meanwhile we 

 must notice that the phrase leads us astray if it is taken 

 literally or woodenly. It includes every form of the clash 

 between individuals and their environing difficulties, all the 

 novel responses that individual living creatures are always 

 making to the pressure of limiting conditions. These re- 

 sponses may take the form of intensified competition, even of 



