Apbil 21, 1916] 



SCIENCE 



549 



Europe in combining these resources, above 

 all in combining them rapidly enough. The 

 European public does not sufficiently real- 

 ize their necessity and interest. And the 

 action of the state necessarily lacks the 

 flexit)ility needful for rapid realization. 

 Thus Pasteur was able to organize the insti- 

 tution which bears his name only at the end 

 of his life, and at the inauguration he was 

 heard to say mournfully, "I enter here de- 

 feated by Time." In America the power 

 and the eagerness which private initiative 

 gives provide for this need. Truly the 

 greatest wonder is that this liberality is 

 generally well conceived and well employed. 

 It is also true that the problems of the 

 day in contemporaneous biology are no- 

 where else attacked at the present time with 

 such activity, perseverance, and success as 

 in the United States. As we look at differ- 

 ent points on the biological horizon, we see 

 the studies on the Mendelian theory of 

 heredity in full development in numbers of 

 laboratories. It will be enough for me to 

 cite in this connection the names of Messrs. 

 Castle and East in this very spot, and that 

 of Mr. T. H. Morgan in New York. In the 

 realm of the physiology and the structure 

 of the cell and of the egg, the researches of 

 E. B. Wilson, and of his pupils on the 

 chromosomes, of J. Loeb on experimental 

 parthenogenesis, of F. R. Lillie on the fer- 

 tilization of the egg, of Calkins and recently 

 of Woodruff on the senescence of the infu- 

 soria, suffice to show the share which this 

 country has had in the advance of knowl- 

 edge. And I ought also to mention numer- 

 ous works on embryology and on the study 

 of the filiation of the cells of the embryo 

 (cell-lineage), on regeneration, on the be- 

 havior of the lower organisms, on geo- 

 graphic distribution and the variations of 

 the species studied from the most diverse 

 sides; all branches of biology are flourish- 

 ing vigorously. In addition, the United 



States, more than any other country, has 

 developed scientific institutions designed 

 for the study of the application of biology 

 to agriculture, to fisheries, etc. 



In the face of this situation, I wish to 

 make it clear at the outset that I have not 

 the least expectation of bringing here a 

 solution of the problem of evolution. I 

 have too full a realization of the extent of 

 the scientific movement aroused by this 

 question in the United States and I hope to 

 derive great benefit myself from my stay 

 here, from the contact which is permitted 

 me with my colleagues and with their labo- 

 ratories. This latter advantage is not the 

 least which arises from the exchange be- 

 tween the two universities. Nor have I the 

 expectation of bringing to you a new solu- 

 tion of the problem, nor of examining it 

 from a special and original point of view, 

 such as might be the case in a single lec- 

 ture or a small number of lectures. 



I will adhere strictly to the point of view 

 of the instructor, taking the question as a 

 whole, expounding it in its older aspects 

 as well as in its more recent ones. The in- 

 terest in these lectures is above all, in my 

 opinion, in the coordination of facts and in 

 their critical examination. As this coor- 

 dination is influenced in a large measure by 

 the surrounding conditions, the view that 

 a naturalist has of them in Paris ought to 

 be interesting here. In questions as compli- 

 cated and as undeveloped as these still are, 

 where we have not reached a precise con- 

 clusion, the relations of facts can not be 

 established in a harsh and unequivocal 

 fashion. This is particularly true of the 

 problem of evolution at the point we have 

 reached. During the last few years very 

 rapid and great progress has been made in 

 our knowledge relative to certain kinds of 

 data; notably heredity and variation. 

 But they have not failed to shake markedly 

 the notions which previously seemed to be 



