12 A History of Botany, 1860-1900 



mental difficulties brought to light the processes of adapta- 

 tion, and showed how the living organism assumed its 

 peculiarities of form and structure in accordance with the 

 nature of the life it had to lead. 



In this way the final blow was given to the dogma of 

 the constancy of species, and evolution through natural 

 selection in the struggle for existence took its place. How 

 great a change was this the researches of the remainder 

 of the century will serve to show. At the outset it opened 

 the way for new investigations, offering them the stimulus 

 of more illuminating ideas and compelling them to new 

 methods, and it succeeded in bringing about a great enthu- 

 siasm for all branches of inquiry. 



The other almost fundamental dogma of the time, Goethe's 

 theory of metamorphosis, also came under review. This 

 doctrine, the outcome mainly of a poetic mind, was, as 

 stated by Goethe himself, difficult to grasp and harder 

 fully to appreciate. As expounded by others it became 

 rigid and exacting. The introduction of the new ideas 

 modified it sensibly, emphasizing the view that the changes 

 in the different parts of the body of the plant, which were 

 described as metamorphoses, are mainly adaptive and 

 consequently traceable to the influence of the environment. 

 Though the theory of metamorphosis gave rise in the 

 later years of the century to considerable controversy, the 

 change in the point of view led to greater clearness of 

 conception and to the abandonment of the somewhat 

 fanciful or ideal attitude with which Goethe's early pro- 

 nouncements were associated. 



To ascertain the position of the science in 1860 it is 

 well to turn to the textbooks of the time, as, though not 

 abreast with the then most recent inquiries, they presented 

 to their readers what were the established opinions among 

 the botanists of the countries of their publication. Germany 

 had produced the majority of the workers on intimate 



