MIGRATIONS AND THEIR SIGNIFICANCE 221 



partly on differences of needs and ideals. Those who would 

 keep the door open are largely employees of labor who need 

 most of it to ''develop" or exploit the resources of the coun- 

 try. Those who wish to restrict belong partly to the class of 

 laborers and low-grade artisans who desire to keep wages 

 high and partly to the old families who fear the consequences 

 of this copious infusion of South-eastern European blood. 

 This difference of opinion must, as is generally the case, be 

 ascribed to ignorance. If we knew the probable consequences 

 upon our national life we would probably be agreed what 

 to do. 



To a biologist it seems that the economic aspects of the im- 

 migration problem will take care of themselves, just because 

 immigration is, from this side, self-regulatory. When wages 

 fall immigration diminishes to a third or a quarter of the 

 volume that it has in times of prosperity and high wages. 

 (Moreover, it is (isn't it?) a rather selfish policy to keep out 

 those who are qualified to become good citizens that we may 

 fatten the faster on their destitution .\ But on its biologic 

 side the problem is real and urgent. How can we keep out 

 defective germ plasm while we admit that which is strong? 

 The attempt to do this by examination of the immigrant is 

 as unscientific as it is inadequate. A person who by all 

 physical and mental examinations is normal may lack in 

 half of hio germ cells the determiner for complete mental 

 development. In some respects such a person is more un- 

 desirable in the community than the idiot (who will prob- 

 ably not reproduce) or the low-grade imbecile, who will be 

 recognized as such and be selected against in marriage, or be 

 sent by his neighbors to an institution where he may be 

 kept from reproducing. N or can the immigration 2 robl£m 

 be sol ved by exclu din£_on _the ground of race or jiative_ 

 country^ No one has suggested excluding the natives of 

 Switzerland, yet a normal woman from the neighborhood of 



