PROGRESSIVE DEVELOPMENT 667 



in which he attempted to account for the changes of form and 

 habits of plants and animals on the earth. His theories established 

 also a foundation upon which plant and animal breeders were able 

 to work. Two of his best known books are Origin of Species and 

 Plants and Animals under Domestication. We have studied about 

 some of his work on pollination (page 56) and his theory of 

 "natural selection" (page 605). 



His interpretation of the ways in which all life changes and 

 develops was due not only to his information and experimental 

 evidence, but also to an iron determination and undaunted energy. 

 In spite of almost constant illness brought about by eyestrain, he 

 accomplished more than most well men have done. He died on 

 the 19th of April, 1882, at seventy-four years of age. 



Other workers. Associated with Darwin's name we must place 

 also the names of two other co-workers on heredity. Alfred 

 Russel Wallace, an Englishman, who, working independently and 

 at about the same time, reached many conclusions similar to 

 those of Darwin. Thomas Henry Huxley did much to make 

 people understand Darwin's work, as he was a wonderful teacher 

 and lecturer. 



In recent years there have been many new facts discovered 

 which make us doubt that Darwin's explanation for some of the 

 phenomena he described may be the best that can be given. But 

 the evidences for the development of plant and animal life are 

 stronger than ever and no thinking scientist can deny this remark- 

 able story which is written in the rocks, and in the relationships of 

 living things as shown in structural and vestigial evidences, in 

 embryological development, and in geographical distribution, all 

 facts that Darwin pointed out after years of study. 



Self-Testing Exercise 



(1) is called the father of evolution (2) 



(3) was the founder of the modern theory of progressive develop- 

 ment. The foundation for Darwin's life work were laid in a 



(4) around the (5) in the ship (6). Alfred Russel 



(7) worked (8) of Darwin, but came to the same 



• 0). 



