THE EFFECT UPON HUMAN EVOLUTION 287 



Varieties of the human race exist as do varieties of dogs. The 

 Pekingese and the fox terrier are as different as the Slav and 

 Latin are different: because of differences in internal secretion 

 make-up. The Slav peasant is definitely subthyroid in his general 

 effect: round head, coarse features, stubby hands, and his stolid, 

 brooding intellectual and emotional reaction. The Latin shows a 

 pronounced adrenal streak in his coloration, his emotivity, his 

 susceptibility to neurosis and psychosis. H. Laing Gordon, a Scot 

 physician, reported that of 700 cases he studied, more than twice 

 as many of duplex eyed individuals (brown or black, i.e., adrenal- 

 centered most often) , were susceptible to the mental disturbances 

 of war as the simplex (blue or gray-eyed, i.e., thyroid-centered 

 most often). He also pointed out that such individuals tend to 

 have a narrow and abnormally arched palate. The Anglo-Saxon 

 tends to be more sharply pituitarized, his features are more clean- 

 cut, his mentality more stable. The Frenchman is rather a cross 

 between the Anglo-Saxon pituitary-centered and the Italian or 

 Spanish adrenal-centered. 



So national resemblances, traceable to climatic influences being 

 repeated from generation to generation upon the endocrines, may 

 be explained physiologically. The physiologic interpretation of 

 history will indeed be found the broadest, including as comple- 

 mentary Buckle's climatic theory, Hegel's ideas on the influence 

 of ideas, and Marx's on the superiority of the economic motives 

 and forces. 



The Races of Mankind 



Arthur Keith, conservator of the Museum of the Royal Col- 

 lege of Surgeons of England, was the first to apply the principle 

 of endocrine differentiation to the problem of the color-lines — the 

 lines which have divided mankind crudely into the yellow, the 

 red, the white and the brown, the Negro, the Mongol, the Cauca- 

 sian, the copper tinted American. It has long been recognized 

 by anthropologists that the differences of color march with dif- 

 ferences in every comparable trait. Thus the ideal Negro is 

 built upon a pattern in which all the elements are specific and 

 singular. When the looms revolve that make him, there is pro- 

 duced a gleaming black skin, kinky black hair, squat wide- 

 nostriled nose, thick protruding lips, large striking teeth, promi- 

 nent jaws, and staring eyes. As his upright carriage and bone- 

 muscle-fat proportions are distinctive, so are his musical voice 

 and his easily wrought upon nerves. In contrast the Caucasian 



