396 



SCIENCE. 



[N. s. Vol. XX. No. 508. 



youth seeking only truth and convinced 

 that only pure truth can bring real prog- 

 ress are the judges to which I gladly sub- 

 mit my conceptions. 



My ideas have grown slowly, and have 

 only reached their definiteness and full 

 development under the protection of the 

 high principles of university freedom. I 

 have needed nearly twenty years to de- 

 velop them and to gather the evidence by 

 means' of which T 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 Amer- 

 ican 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 ex- 

 pected 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 perse- 

 verance 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 evo- 

 lution 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, comprehensive and hopeful dur- 

 ing a whole century of continuous research. 

 Everywhere it is recognized to take the 

 leadership. It has been the means of in- 

 numerable discoveries, and whole sciences 

 have been started from it. Embryology 

 and ontogeny, phytogeny and the new con- 

 ceptions of taxonomy, paleontology of 

 plants and of animals, sociology, history 

 and medicine, and even the life history of 

 the earth on which we live, are in reality in 

 their present form 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 inaugurated 

 in this country. I refer to the pure uni- 

 versity studies and the work of the agri- 

 cultural stations. Highly valuable is the 

 application of science to agriculture in the 

 improvement of races. Each of you knows 

 how this artificial production of races of 

 animals and plants was one of the great 

 sources of evidence on which Darwin 

 founded his theory. But at his time the 

 available evidence was only very scanty 

 when we compare it with the numerous 

 facts and the improved methods which now 

 are the result of half a century 's additional 

 work. America and Europe have com- 

 bined in this line, and the vast amount of 

 facts, heaped up by numerous investigators 

 and numerous well-equipped institutions, 

 has produced quite a new basis for a critical 

 review of Darwin's theory. 



I have tried to combine all these too dis- 

 persed facts and to bring them together, 

 in order to obtain a fuller proof for the 

 main points of Darwin's conception. In 

 one subordinate point my results have been 

 different from those of Darwin, and it is 

 this point which I have been invited by the 



