324 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1916. 



solution of the problem, nor of examining it from a special and 

 original point of view, such as might be the case in a single lecture 

 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 interest in these lectures is, 

 above all, in my opinion, in the coordination of facts and in their 

 critical examination. As this coordination 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 

 complicated and as undeveloped as these still are, where we have 

 not reached a precise conclusion, the relations of facts can not be 

 established in a harsh and unequivocal fashion. This is particu- 

 larly 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 mark- 

 edly the notions which previously seemed to be at the very founda- 

 tion of evolution. One of my compatriots, an ardent disciple of 

 Lamarck, F. Le Dantec, wrote even as far back as eight years 

 ago a book bearing the significant title "La Crise du Transform- 

 isme,"^ in which he brought out the contradictions in question, 

 contradictions which, according to him, were to result in the i*uin 

 of the very idea of transformism. Since that time opposition has 

 become even more marked, and at the present day, either tacitly 

 or explicitly, certain of the most authoritative men, by their works, 

 hare arrived very near to a conception which would be the negation 

 of transformism rather than its affirmation. 



The term "evolution," in French, at least, has had historically 

 two contrary meanings. In the eighteenth century it was the ex- 

 pression of the theory of the preformation or " emboitement " of 

 the germs, according to which the lot of every organism was deter- 

 mined from the beginning. The succession of generations was only 

 the unfolding (evolutio) of parts that existed from the beginning. 

 In the nineteenth century, and it is in this sense that it is always 

 used now, it had an opposite sense ; it is the synonym of transform- 

 ism and it signifies the successive transformation of animal or vege- 

 table organic types, not realized beforehand, in the course of the 

 history of the earth, under the influence of external causes. Now, 

 if one admits the general value of certain of the ideas recently ex- 

 pressed, evolution would be only the unfolding of a series of phases 

 completely determined in the germs of primitive organisms. It is a 

 reversion, under a modern form, to the idea which the word evolution 



1 Nouvelle collection scientiflque," Paris, Alcan. 



