CHAPTER XXXIII 

 EXPERIMENTAL EVOLUTION 



445. A New Method of Study. — Previous to Darwin's 

 time the study of plants and animals, was carried on 

 chiefly by observations in the field. The science was 

 largely descriptive — a record of what men had observed 

 under conditions over which they did not endeavor to 

 exercise any control; it was accurately named "Natural 

 History" — a description of Nature. But Darwin and a 

 few of his contemporaries, especially among botanists, be- 

 gan to make observations under conditions which they 

 determined and largely regulated. In this way the 

 problems were simplified, observation became more ac- 

 curate, and the endeavor was made to assign the prob- 

 able causes of the observed phenomena. With the intro- 

 duction of this experimental method, science began to make 

 rapid strides, and, more than ever before, facts began to 

 be, not only recorded, but interpreted and explained. 



446. Hugo de Vries. — The director of the Botanic Gar- 

 den in Amsterdam, Holland, Hugo de Vries, was among 

 the first to demonstrate that the method of experiment 

 may be applied to the study of evolution. His plan was 

 to secure seed of a given species from a plant which he 

 believed to be pure with reference to a given character, 

 that is, not contaminated or mixed by being cross-pollin- 

 ated with another variety or species. The characters of 

 the parent plant were carefully noted and recorded by 



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