18 
PROOFS OF EVOLUTION. 
dominant among birds, those having the most 
beautiful plumage, or sweetest songs, winning the 
choicest mates. The former fight for existence; 
the latter, like the warriors bold of the Middle 
Ages, battle for love. This warfare is in the 
world to-day wherever there are life and move¬ 
ment. These principles of evolution are still 
everywhere operating. Heredity preserves these 
jewels of descent, without which we would go 
back to “ chaos and old night.” 
