THE STRUGGLE FOR EXISTENCE. 91 



do. This ought to convince us of our ignorance on the 

 mutual relations of all organic beings — a conviction as 

 necessary as it is difficult to acquire. All that we can 

 do is to keep steadily in mind that each organic being is 

 striving to increase in a geometrical ratio ; that each at 

 some period of its life, during some season of the year, 

 during each generation or at intervals, has to struggle for 

 life and to suffer great destruction. When we reflect on 

 this struggle, we may console ourselves with the full be- 

 lief that the war of nature is not incessant, that no fear 

 is felt, that death is generally prompt, and that the vigor- 

 ous, the healthy, and the happy survive and multiply. 



