338 THE AMERICAN NATURALIST [Vol.LVI 



In the case of Cometj Foljambe and Favorite (cow) 

 each appears twice in the pedigree of the sire and three 

 times in the pedigree of the dam. However, only those 

 pedigree paths which connect sire and dam and which do 

 not pass through the same animal twice are counted. The 

 listing of Favorite (252) and Phoenix as common ances- 

 tors eliminates all but one path in each case as regards 

 Foljambe and Favorite cow. The remaining paths are 

 those due to the common descent of Bolingbroke, the 

 sire's sire and Phoenix as the dam's dam from the above 

 two animals. 



By tracing the pedigrees back to the beginning of the 

 herd book, the coefficients cf inbreeding are slightly in- 

 creased. This meant going back to the seventh genera- 

 tion for one common ancestor of the sire and dam of 

 Favorite. The coefficient in the case of Favorite be- 

 comes .192 instead of .188 and that of Comet .471 instead 

 of .469. Eemote common ancestors in general have little 

 effect on the coefficient. It will be noticed that Comet 

 has a degree of inbreeding almost equal to three genera- 

 tions of brother-sister mating or an indefinite amount of 

 sire-daughter mating where the sire is not himself inbred. 



