240 



The Journal, of Heredity 



blondness must lie met. Among tlic 

 dark races, variations which pnxhice 

 relatively little dilution of hair color 

 are apt to i)ro(luce photo])hohia, nystag- 

 mus, and imperfect vision. lUit these 

 eye defects seem no more common in 

 Scandinavia and the surrounding re- 

 gions than elsewhere. It is. however, 

 quite likely that with selection for blond- 

 ness (jf the hair, there would be selec- 

 tion against the accompanying eye de- 

 fects. An adjustment in regional differ- 

 entiation may thus have been reached 

 by which eyes come to be affected less 

 than skin and hair by the dilution fac- 

 tors. There is also some evidence from 

 Pearson's data that in Scandinavia and 

 Northern Germany eye colors are rela- 

 tively darker for any given hair color 

 than in the surrounding countries. 

 Flaxen hair with dark eyes seems to be 

 quite common there, while very rare, 

 for examjjle. in Great liritain. 



The discussion so far has neglected 

 racial lines. The anthropologists are 

 generally agreed that there are three 

 main racial types in Eur()])e. Thev hold 

 that Europe was originally inhabited by 

 d.olichocephalic races related to those 

 of northern Africa and southwestern 

 Asia. At ])resent only the fringe of 

 Euro])e has such types in anything like 

 purity. The heart of the continent 

 from the Ualkans to France is inhal)ited 

 largely by brachicephalic peoi)le. be- 

 lieved to be derived from the highlands 

 of central Asia where si nil a r people 

 still live, connected witli the luud])e;ui 

 type through the Armenians of Asia 

 Minor, 'ibis so called Ali)ine race is 

 typically dark in hair and eye where 

 found presumably in the greatest ])urity 

 in Asia and southeastern Europe. 



'i'he original dolichoce])halic races of 

 Europe had an immense time in which 

 to become differentiated from each 

 other. These differences are manifest 

 in the dolichocephalic peoples living now 

 around the fringe of luirope. Thus the 

 inhabitants of Southern Italy. Spain. 

 and Southern France of the Mediter- 



ranean race are dark and relatively 

 short. Among the older races of the 

 British Isles somewhat diff'erent from 

 either the Mediterraneans or the Nor- 

 dics, the inhabitants range from medium 

 (in Wales) to the tallest in Europe, and 

 all are especially angular featured ac- 

 cording to Ripley, and are rather dark. 

 The Scandinavians, North Germans, 

 and Finns of the Nordic race are rather 

 tall, less angular in features and very 

 fair. It is clear that the dilute varia- 

 tions arose among the northern dolicho- 

 cephalic people probably with somewhat 

 diff'erent centers of dispersal for the 

 two kinds of dilution, as noted before. 

 (\^nstant mixture with the dark Medi- 

 terraneans, Alpines, and Mongols ])ro- 

 duced the zone of segregating colors. 



CONCLUSION. 



In conclusion we may say that certain 

 rare traits peculiar to families such as 

 premature grayness. piebaldism. and al- 

 binism (in some families) follow easily 

 determined rules of inheritance. Pre- 

 mature grayness and ]iiebaldism behave 

 as unit dominants. Piebnld in some fam- 

 ilies is sex-limited. Albinism is in cer- 

 tain cases a unit recessive. The com- 

 mon variation of eye. hair, and skin 

 color cannot yet be said to be completely 

 analyzed. The most important varia- 

 tions seem to be of two kinds. First is 

 general reduction of color (class lb), 

 affecting red pigment and eye color at a 

 higlior thresliold than black of hair, but 

 ])ro(h!cing general albinism in extreme 

 cases. lilack hair with blue eyes is 

 caused bv moderate variation of this 

 kind. Second is dilution of black onl\- 

 (class 2a.,) which affects hair. skin, and 

 eves, and in extreme cases produces a 

 red haired ty])e of albino. l\ed hair 

 with blue e\es is typical of moderate 

 dilution of this type. Goiubinations of 

 the two kinds of variation produce the 

 blond types which jiass into more or less 

 perfect albinism much more easily than 

 when either type of variation is alone. 



