608 POPULAR SCIENCE MONTHLY. 



to the environment for the final solution of many of the great prob- 

 lems of Nature. In this case we have to do with one of the most 

 sudden and radical changes of environment known to man. Every 

 condition of city life, mental as well as physical, is at the polar 

 extreme from those which prevail in the country. To deny that 

 great modifications in human structure and functions may be 

 effected by a change from one to the other is to gainsay all the 

 facts of natural history. 



Our long series of articles now draws to a close. It has been 

 shown with what infinite pains, slowly through hundreds of gen- 

 erations, human beings in Europe have been shaping themselves 

 to the conditions imposed by Nature. We have followed men in 

 their migrations over the face of the continent; we have analyzed 

 the forces making for change, which have played upon them; we 

 have seen how tenaciously they have clung to the type of their 

 ancestors throughout all the vicissitudes of ages. Whether twen- 

 tieth-century urban life, with all the social changes which it 

 implies, will finally eradicate all traces of ethnic descent remains 

 to be seen. Certainly the pages of ethnic history, written in man's 

 physical constitution, are rapidly blurring before our eyes. To 

 be deciphered at all, they require the instant attention of Euro- 

 pean scientists. As for us in America, our field of investigation is 

 mapped out with equal clearness. We know with some certainty, 

 thanks to the unselfish and stupendous exertions of such men as 

 Beddoe, Collingnon, Ranke, Livi, and a host of their fellows in 

 Europe whose work we have been outlining, what is the raw mate- 

 rial of which our heterogeneous American population is to be com- 

 posed. They have analyzed the sources of the great human stream 

 which is flowing continually westward to our shores. They have 

 acquainted us with the physical character of the communities 

 whence come those who, as immigrants, cast in their lot with Amer- 

 ica for good or ill. It behooves us at once to know whether we 

 are drawing off the scum, the lees, or the pure waters in this in- 

 flowing tide. Then, again, we have to determine the effects of this 

 novel life — its climate, its social conditions, its material prosperity, 

 and, above all, its ceaseless intermingling of all strains and classes — 

 upon the physical constitution of the original ethnic stocks. Such 

 are the problems which confront us. May we take up the scientific 

 burden where our European confreres must of necessity lay it down; 

 and, in the same devotion to knowledge for its own pure sake, bear 

 it a step further along the way! 



