HUMAN RACES 1 57 



established of which are known as the human races. These 

 races differ much in age as well as in distinctiveness; and the 

 oldest and most distinct have appeared to some students to 

 deserve the term of species rather than races. 



The question hinges largely on the concept of a "species." 

 This concept and its definition have never been made as 

 clear as one would wish. A perfect, universally valid defini- 

 tion of a species seems in fact impossible. A species may 

 merely be said to be a well-defined, autonomous and per- 

 sistent organic unit, living in a free state of nature, not 

 grading freely into any other unit, and generally of less 

 perfect fecundity outside than inside of its limits. A species 

 moreover differs from all other species not only morphologi- 

 cally, but also in its physiological manifestations, and in its 

 "psychic" behavior. 



When we apply such a concept and definition to man, 

 we fail to estabhsh separate species in this genus. Even 

 man's most distinct strains intergrade very substantially 

 with others, somatologically, physiologically and in mental 

 behavior; they interbreed freely and, under normal con- 

 ditions, rear normal lastingly fecund progency; and 

 all are changeable in the direction of other units of the 

 group, under altered conditions. There is therefore, as 

 well recognized already by Darwin and many other eminent 

 older students of the question, no justification for the 

 assumption within the human genus of more than one true 

 species, and the different strains of man may properly 

 be regarded as just subspecies, varieties, or, most simply 

 and intelligibly, as races. 



ORIGIN OF HUMAN RACES 



The phenomenon of raciation, i.e. of differentiation into 

 races, is common to all living organisms. It is an important, 

 and in higher organic forms probably necessary, step 

 towards speciation, or the formation of species. 



The formation of races in any geographically extensive 

 group is more or less continuous, according to circumstances 

 such as environmental differences, isolation, in-breeding 

 and mix-breeding. Judging from analogies among the 

 existing anthropoid apes, it is safe to assume that there 



