548 



THE AMERICAN NATURALIST 



[Vol. LI 



respect of the distribution of its ancestral repetition. Out 

 of actual laboratory experience has been developed the 

 more simple and rigorous analysis of the matter pre- 

 sented in this paper. 



3. It would appear that the briefest and simplest way 

 to make clear our concept of kinship measurements, its 

 use in the analysis of inbreeding, and its practical appli- 

 cation to pedigrees, is to carry out the work on some con- 

 crete examples, given by actual pedigrees showing a 

 rather high degree of inbreeding or relationship. This 

 we shall accordingly proceed at once to do, taking as our 

 first example the pedigree through five ancestral genera- 

 tions of the Jersey cow Letty's Fancy Lady (241551). 



The pedigree (for five ancestral generations) of this 

 cow is presented in Tables I and II. Table I gives the 

 pedigree of her sire, Rioter's St. Lambert King (58644), 

 and Table IT gives the pedigree of the dam of the cow, 

 Letty's Fancy (160320). Tables I and II together, there- 

 fore, give the complete pedigree (to the extent already 

 indicated) of the cow herself. The reason for splitting 

 the pedigree into two parts in this way in its presentation 

 will be apparent as we proceed. The numbers preceding 

 the names of the animals are the registry numbers in the 

 Herd Books of the American Jfersey Cattle Club. 



In Tables I and IT the symbols have the following sig- 

 nificance: A solid circle indicates a primary reappearance 

 of an ancestor, having reference to the pedigree of Letty's 

 Fancy Lady as a whole, and an open circle indicates an 

 entailed reappearance consequent upon the primary re- 

 appearance denoted by the solid circle. A solid square 

 indicates a primary reappearance in the pedigree of the 

 sire of Letty's Fancy Lady, considered hy itself and with- 

 out reference to her dam's pedigree; an open square de- 

 notes reapi>earance consequent upon those indicated by 

 the solid squares. Finally, a solid diamond indicates a 

 ])T imary reappearance of an ancestor in the pedigree of 

 the dam of Letty's Fancy Lady, considered hy itself ,-ss[h.\\e 

 tlie open diamonds denote the corresponding entailed re- 

 appearances. 



