AN INTRODUCTORY ORIENTATION 5 



hangs threateningly over the organic world. The attainment of 

 any degree of complexity or perfection of organization is no 

 guaranty against deterioration. There is not the slightest ground 

 for believing that man himself is in any degree shielded from its 

 insidious influence. In fact, it is not improbable that many 

 existing peoples have descended from ancestors who were more 

 favored with natural gifts, and we should bear in mind the possi- 

 bility that our own civilization may become one with Nineveh 

 and Tyre. 



If human progress involves the successive exhaustion of the 

 best blood of those nations which gain the ascendency in the 

 development of culture, it can scarcely lead to any other result 

 than a general deterioration of the human species. If there have 

 always been races of superior inheritance, such as those of Nordic 

 stock, which have remained upon a relatively low cultural level, 

 and which were capable of acquiring the civilization of the 

 decadent nations which they supplanted, it by no means follows 

 that the human species will always be so favorably situated. Mr. 

 Seth Humphrey has recently drawn attention to the "exhaustion 

 of reserves" which are at present available for carrying on the 

 work of civilization. Of all our national resources the most 

 important is our supply of men of superior stock. And we are 

 approaching a period in which the problem of the conservation of 

 this resource is becoming more and more pressing. 



The biological situation of our race is at present in many 

 respects unique. In the earlier stages of man's evolution develop- 

 ment was mainly along divergent lines. The spread of mankind 

 over the continents and islands of the globe brought about the 

 formation of more or less completely isolated stocks, subjected to 

 different conditions of environment. This resulted in breaking up 

 the human species into a great multitude of divergent groups, in a 

 manner which closely parallels the diversification of species of 

 plants and animals subjected to the combined influence of isola- 

 tion and varied surroundings. Few species of organisms present so 

 great a variety of hereditarily diverse strains as our own. And 

 even if we divide Homo sapiens into several distinct species, 



