INHERITANCE OF WHITE FORELOCK 



S. J. Holmes and Richard O. Schofield 



University of California, Berkeley, Calif. 



THERE are a number of cases on 

 record in which a lock of white 

 hair has been traced through 

 several generations. In general 

 the white lock behaves as a typical 

 dominant character, manifested by 

 males and females alike. ^ In a family 

 which has come to our notice, the white 

 lock has been found to occur only in 

 the males, although the females in the 

 family, at least some of them, are 

 capable of transmitting this peculiarity 

 to their sons. 



The lock occurs in the center of the 

 fore part of the scalp. The region 

 affected is about the size of a half 

 dollar, and the hairs making the lock are 



slightly larger than those surrounding 

 it and which may be of any general 

 color. The lock is not evident in 

 children, but makes itself manifest 

 about the period of puberty. In all 

 cases in this family the sons of affected 

 males are also affected, although un- 

 affected males might be expected to 

 occur also. This distribution is in all 

 probability due to chance. The females 

 who are heterozygous do not manifest 

 the white lock, but all of the daughters 

 of the affected males have transmitted 

 the character to their sons. Some of 

 the females have no affected offspring, 

 either because they are nulliplex or be- 

 cause their sons happened to escape. 



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PEDIGREE OF FAMILY WITH WHITE FORELOCK 



Squares denote males and circles females; affected individuals are indicated by black squares. 

 Not once in the family history has the forelock appeared in a female; the probabiHty that 

 this is not due to mere chance is very great. Other families have been studied, in which 

 this white spotting factor affected both sexes alike. (Fig. 12.) 



1 The pedigree of one such family, extending over six generations, was published by Newton 

 Miller m the Journal of Heredity, VI, pp. 165-169, 1915. 



359 



