174 HEREDITY IN RELATION TO EUGENICS 



e. Congenital dislocation at the thigh bone — ^pelvis joint. — 

 This is a peculiarity that usually runs in families. It is 

 doubtless due to a laxness in the ligaments by which attach- 



I lBfc» 



Fig. 156. — Pedigree of absence of clavicles. The father, 1, 1, has deformed 

 claviclea. By a normal wife he has 7 children affected as follows: II, 1, has a 

 slightly deformed clavicle; II, 2, has a deformed right clavicle; II, 3, has nor- 

 mal clavicles but a prominent transverse process of the last cervical vertebra; 

 II, 4, has clavicles nearly absent and also the clavicular portion of the great 

 chest muscle; II, 5, has a peculiar kink in the clavicles; II, 6, is normal; II, 7, 

 has a deformed right clavicle. Carpenter, 1899. 



ment is made. Several pedigrees have been worked out by 

 Nareth (1903) of which one is reproduced here (Fig. 157). 



No evidence appears as to the amount of consanguineous 

 marriage except in one case. The pedigree looks like one 



o^ 



distant 



I 8N children | 



Fig. 157. — Pedigree of a family showing congenital dislocation of the hip. 

 Affected persons (black symbols) descend from unaffected, suggesting that 

 the condition is due to a defect. Senator and Kaminer, 1904. 



of albinism and suggests that congenital dislocation , is a 

 defect. In that case the marriage of related persons, even 

 though normal, is to be discouraged, but an affected person 

 by marrying into new blood may expect normal offspring. 



