134 Maine: agricultural kxperiment statiox. 1913. 



Illustration IV. Thl Pedigree of the Jersey Cow, Figgis 

 20th oE Hood Farm (190306). 



Figgis 2oth of Hood Farm (1903061 is a cow \vhich, in 

 official test for advanced registry, produced as a two year old 

 437 lbs. 14.4 oz. butter fat. This is a high record. The com- 

 plete pedigree of this animal has been worked out for 12 ances- 

 tral generations, and the coefficients of inbreeding calculated. 

 Twelve generations cover practically the whole of the known 

 pedigree of this cow. On account of its great length it is 

 impossible in the space here available to reproduce this pedi- 

 gree. Nor is it necessary. The inbreeding coefficients in a 

 quarter of a page give more clear and definite information 

 regarding the amount of inbreeding practised in the breeding 

 of Figgis 20th than could any visual inspection of the pedigree 

 itself. Furthermore the list of names in Table 4 shows just 

 what animals appear more than once in the pedigree, and how 

 frequent are their reappearances. 



Table 4 is precisely the same sort of table for Figgis 20th 

 that Table 3 is for Bess Weaver. 



In dealing with this and all other pedigrees it is assumed, in 

 the absence of information on the point and the impossibility 

 of acquiring any, that any imported animal for which there is 

 no further pedigree, was not inbred to any degree whatsoever. 

 This is probably not often strictly true, but, on the other hand, 

 some assumption must be made, and this puts all individuals on 

 an equal footing. It is in accord with the principle laid down 

 earlier (p. 127) that in pedigree analysis all individuals must be 

 considered to be unrelated until the contrary is proved by the 

 evidence of their ancestry. After all, the only thing we can 

 possibly measure is the inbreeding shown in the recorded 

 pedigree. All that happened prior to the beginning of the 

 record must be a matter of assumption. The same assumption 

 should, however, be made for all cases. What this assumption 

 really means practically is that, in all cases of analysis of actual 

 pedigrees, which are bound after a time to come to an end, the 

 values of the coefficients of inbreeding obtained are lower limit- 

 ing values. They signify that the intensity of inbreeding in a 

 particular case could not have been less than that indicated ; it 



