Wright : 



Color Inheritance in Mammals 



239 



The main difference is that such red 

 eyed white guinea pigs have no more 

 dikition of the eyes than red eyed black 

 ones (EE Cr Cr), a point explained by 

 the different character of the guinea-pig 

 restriction factor (of class 2a2) and 

 the human variation for red hair of 

 class 2a3. The evidence does not yet 

 warrant the acceptance of any unit 

 factors for either of these kinds of 

 variations in man, though there is much 

 evidence of segregation. If we suppose 

 that black is only imperfectly dominant 

 over extreme reds (evidence for which 

 has already been noted) we can easily 

 account for the numerous auburn and 

 chestnut browns among the relatives 

 of European albinos. 



COLOR AND RACE 



This leads to a consideration of the 

 racial distribution of human color 

 variations. Pearson and his collabora- 

 tors have shown that dilute variations, 

 probably of both kinds, occur occa- 

 sionally in all or most of the dark- 

 colored races. Dark hair with green 

 eyes and reddish-brown hair with dark 

 eyes are found as well as the more ex- 

 treme albinotic types. Such variations 

 could doubtless develop blond races, if 

 given an advantage in selection. In 

 most parts of the world, however, such 

 variations with their lack of adaptation 

 to excessive sunlight are rather selected 

 against. In the foggy region of north- 

 ern Europe, however, conditions are 

 favorable. Here selections seems to 

 have favored dilute variations of all 

 kinds, probably largely through mar- 

 riage. A traditional association of 

 blondness with nobility or racial pre- 

 eminence would lead to such a result. 

 Around the shores of the Baltic and the 

 North Sea we find typically blue-eyed, 

 flaxen haired people, who, we must sup- 

 pose, possess variations of both classes 

 lb and 2ao to a marked extent. Among 

 the Lithuanians and certain of the Finnic 

 peoples along the east shores of the 

 Baltic (Livs, Esths, Tchouds ) this 

 blondism reaches its maximum accord- 

 ing to Pearson, Ripley, ^^ and others. 

 The hair is described as white or yel- 



lowish white, and the eyes, very pale 

 blue. In Scandinavia, North Germany, 

 and parts of Britain the same extreme 

 blond type is common. Surrounding 

 the area of extreme blondisin we find a 

 zone of segregating colors. Dark hair 

 with blue eyes and red hair with dif- 

 ferent eye colors occur quite frequently 

 as well as the fully blond or brunette 

 types. The British Isles, northern 

 France, southern Germany, and north- 

 ern Russia are in this zone, and also 

 the more remote parts of the Avorld 

 settled by descendants of these people. 

 The data of Holmes and Loomis from 

 Wisconsin is a good example of this 

 zone. Outside of this zone of segrega- 

 tion, in Europe, are the typically bru- 

 nette populations of Southern and 

 southeastern Europe and Asia. 



We have treated both variations of 

 class lb and 2a, as centering around the 

 Baltic and fading out in all directions. 

 There is some evidence, however, that 

 the zones of frequency of the two kinds 

 of variations are not quite concentric. 

 Dark red hair, according to Ripley, is 

 characteristic of the Finns away from 

 the coast (c. g., the Votiaks and Zyri- 

 ans). It is common even in Western 

 Siberia, as among the \'oguls and Os- 

 tiaks. Ripley also says that some tinge 

 of red is almost universal in the Rus- 

 sians of the north and is common in 

 Hungary and parts of Austria. It thus 

 seems probable that dilution factors of 

 class 2a3 are distributed much farther 

 to the east than those of class lb. In 

 the west of Europe, the two kinds of 

 variation seem to fade out more nearly 

 together, so that both black hair with 

 blue eyes and red hair are common 

 throughout the British Isles. However, 

 black hair with pale blue eyes is most 

 characteristic of the Gaelic speaking 

 portions of Scotland and Western Ire- 

 land. Ripley speaks of this combina- 

 tion as highly characteristic of the Bre- 

 tons and it is even said to be not 

 uncommon in Spain. Apparently varia- 

 tions of class lb have somewhat the 

 greater western spread. 



A difficulty in this interpretation of 



'"Ripley, W. Z., 1899, "The Races of Europe," 624 pp. 



