No. 609] 



STUDIES ON INBREEDING 



553 



K, = 0, K, = "^^^ = 37.50. 



Expressed in words these coefficients mean that 

 Rioter's St. Lambert King and Letty's Lady are related 

 to the amount or degree of 25 per cent, in the third, and 

 37.5 per cent, in the fourth ancestral generation. 



In Fig. 1 are shown the total inbreeding (solid line and 

 dots), the relationship (dashes and open circles), and the 

 partial inbreeding (dots and crosses) curves for Letty's 

 Fancy Lady. 



Finally we have, from (iv), the following coefficients of 

 partial inbreeding due to relationship. 



_50(0)_, 



— 43.75 

 j^^r, 50 (37.j 



AVe thus see that of the total inbreeding obst^-ved in the 

 third aiicc^tia] ,<ienorntion of Letty's Fancy Lady, none is 

 due to rclatioiislii]) between her sire and dain; of that 

 observtMl in tlic fourth nnco-tral ii-ciieration, 2S.57 is due 

 to such rclatioti^hli.: and finally, of that observed in the 

 fiftli nnrc^tral uvik tat ion. one thinl arises because of re- 

 lationship U^Uxvvu -\vi^ an.l .lam. 



4. Let n^ noxt cotr^idrr an exanipl.^ of mensnring rela- 

 tionship in.loiM''i(lontly, altouvther apart from con^idora- 

 tion of inhroo.ling. \Vp may take a ViMy simple case af- 

 forded l)y the two milking shorthorn cows. Imp. Milk 



