pit 



INHERITANCE OF A PIT IN THE SKIN 

 OF THE LEFT EAR 



Jamks Ernest Kindred 

 Biological Labonilor;/, Western Reserve University 



IN DISCUSSING the characteristics 

 of the ears of a group of people in 

 connection with Schofield's paper 

 (1917) on the inheritance of the bi- 

 lobed ear, one of the members of the 

 group called attention to the fact that 

 she had a bi-lobed e.ir, but did notknow 

 of such a condition in any of her 

 relatives. Her mother then remarked 

 that she had a peculiar pit on the side 

 of her left ear. Upon examination of 

 this ear, a small pit was observed in 

 the skin of the proximal end of the 

 ui)per part of the helix. The accom- 

 panying sketch shows its relative posi- 

 tion. My informant then told me that 

 this pitting was a distincti\e mark in 

 her family and by carefully questioning 

 her, I learned the following interesting 

 facts concerning the inheritance of this 

 peculiar marking. A graphic summary 

 of the inheritance of this pit is given in 

 the chart on the opposite page. 



As far as the propistus could recol- 

 lect, the marking was first noted in her 

 paternal grandfather (I, 1). Her fa- 

 ther (II, 2), one of eight children, had 

 the pitted conditif)n, and although 

 she did not know whether or not his 

 sisters or brothers were so marked, it 

 seems more than likely that they were, 

 becau.se some of her cousins had a 

 pitted helix. In the third generation 

 there were four indi\iduals, 2 girls and 

 2 boys, with the pitted helix. The 

 [)roi)istus (III, 7), is one of the girls, 

 her daughter ( I\', 7) does not haAe the 

 pitted helix. The sister of the propis- 

 tus (III, 9), also having the pitted 

 helix, is married and has five children, 

 one daughter (IV, 8) ha\ing the pitted 

 helix. None of the boys with pitted 

 helix in generation III, married. An- 

 other sister of the propistus (III, 4), not 

 pitted herself, is married and has six 

 children, two bo>s and four girls. 

 Both of the boys (IV, 4, 5j have the 



Position of the inherited pit. (Fig. 17.) 



pitted helix. A brother of the propis- 

 tus (III, 14) does not have the pitted 

 helix, but his only son has. The pro- 

 pistus states that in all cases the mark- 

 ing is on the same spot of the same 

 ear (left). 



Thus in this fraternity there is some 

 factor inherited which has to do with 

 the formation of the skin in the region 

 of the proximal end of the helix. The 

 pitting occurs in some individuals of 

 each generation from the time of its 

 appearance and ma>' be transmitted 

 by individuals not marked themselves. 

 Further, it may be transmitted In- 

 either sex. In some cases the otTspring 

 of unpitted parents are pitted, while in 

 other cases the pit does not occur in 

 the offspring of a mating in which one 

 or the other of the parents is pitted. 

 Judging from the manner of its appear- 

 ance, the marking is neither dominant 

 nor recessi\e, but must fall into the 

 intermediate doubtful class of incom- 

 plete dominance. 



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