CHAPTER VIII 

 EXPERIMENTAL EVOLUTION 



81. 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, began to 

 make observations under conditions which they determined 

 and largely regulated. In this way the problems were 

 simplified, observation became more accurate, and the 

 endeavor was made to assign the probable causes of the 

 observed phenomena. With the introduction 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. 



82. 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 the origin of species. 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-pollinated with another variety or species. The 



