I 



FIFTY YEAES OF DARWINISM 



One of the centennial addresses in honour of Charles 

 Darwin, read before the American Association for the 

 Advancement of Science, Baltimore, Friday, January 1, 

 1 909. Eevised and extended. 



On this historic occasion it is of special interest 

 to reflect for a few moments on the part played 

 by the New World in the origin and growth of 

 the great intellectual force which dominates the 

 past half-century. The central doctrine of evolu- 

 tion, quite apart from any explanation of it, was 

 first forced upon Darwin's mind by his South 

 American observations during the voyage of the 

 Beagle ; and we may be sure that his experience 

 in this same country, teeming with innumerable 

 and varied forms of life, confirmed and deepened 

 his convictions as to the importance of adaptation 

 and thus prepared the way for Natural Selection. 

 Wallace, too, at first travelled in South America, 

 and only later in the parts of the Old World 

 tropics which stand next to South America in 

 richness. 



Asa Gray in the New World represents 

 Sir Joseph Hooker in the Old, as regards the 

 help given to Darwin before the appearance of 



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