No. 562] THE PROBLEM OF INBREEDING 593 



this sort a very simple one in which there is little inbreed- 

 ing. This is the pedigree for five ancestral generations 

 of the thoroughbred horse, Postumus. This pedigree is 

 given by Bunsow, 8 and is here reproduced without change 

 .of arrangement, although the plan used of placing the 

 dam above the sire instead of below is contrary to the 

 general American and continental usage. 





Pedig 



ree Table VI 

 Breeding of Postur 





1 



^ j { Fernandez 



( X Vedette 



\ XVo7tigeur KWa> 

 f Isolene 



1 



I 



1 





{ Macaroni 



lDo„ca s .er 

 f Little Fairie 



j Thormanby 



f Eileen Home 

 | XThormanby 



/ Lacerta" 61 ' 

 1 Hornsea 

 f Margaret 



i 



i 



I 





1 Flying Dutchman 

 f Mrs. Ridgway 



J Fann'yDawson filly 



f BarliTle 

 1 Boy Middleton 

 [ Nan Darell 

 1 Birdcatcher 







In this pedigree every animal that has already ap- 

 peared in a lower ancestral generation is marked with an 

 "X," indicating that it is to be "counted out," that is, 

 can not be regarded again as a different ancestor. 



We then have for the successive coefficients of inbreed- 

 mg the following values : 



■Bunsow, R., "Inheritance in Race Horses," Mendel Journal, Vol. I, 

 pp. 74-93, 1911. 



