366 THE EVIDENCE OF EVOLUTION. 



and convinced that only pure truth can bring real progress are the 

 judges to which I gladly submit my conceptions. 



My ideas have grown slowly, and have only reached their defini- 

 tcness and full development under the protection of the high prin- 

 ciples of university freedom. 1 have needed nearly twenty years 

 to develop them and to gather the evidence by means of which I 

 hope to convince you. I kept my secret until some years ago, and 

 worked only for myself. In this respect old universities, as ours are 

 in Europe, have a distinct advantage over your young American 

 institutions. With you all is sparkling and boiling, with us it is the 

 quietness of solitude, even in the midst of a busy city. But your 

 students and teachers are expected to show what they are doing, 

 and to produce their results at short intervals. In Europe, on the 

 contrary, we are trusted and left free even on this point. Hardly 

 anybody has ever asked me what I was doing, and even those who 

 from time to time visited my garden were content with what I 

 could show them, without telling my real difficulties and my real 

 hopes. 



To my mind, this is a high privilege. The solution of the most 

 intricate problems often does not require vast laboratory equipment, 

 but it always requires patience and perseverance. Patience and 

 perseverance in their turn require freedom from all pressure, and 

 especially from the need of publishing early and often unripe re- 

 sults. Even now I would prefer to spend this hour in recounting the 

 obligations which the doctrine of evolution is under to such men 

 as Lamarck and Darwin. I should like to point out how they have 

 freed inquiry from prejudice and drawn the limits between religion 

 and science; how they have caused the principle of evolution to be 

 the ruling idea in the whole dominion of the study of the organic 

 world, and how this idea has been suggestive and successful, com- 

 prehensive and hopeful during a whole century of continuous re- 

 search. Everywhere it is recognized to take the leadership. It has 

 been the means of innumerable discoveries, and whole sciences 

 have been started from it. Embryology and ontogeny, phylogeny 

 and the new conceptions of taxonomy, paleontology of plants and 

 of animals, sociology, history and medicine, and even the life history 

 of the earth on v/hich we live, are in reality in their present from 

 the products of the idea of evolution. 



Instead of telling you of my own work, I should like to sketch 

 the part which of late the scientists of the United States have taken 

 in this work. Mainly in two lines a rapid advancement has been 



