DAIRY, SEED IMPROVEMENT, STOCK BREEDERS' MEETINGS. 223 



has to do with a system of recording types of pedigrees in 

 experimental or other breeding operations. This will chiefly 

 be of use to those who are keeping precise records and breed- 

 ing more or less along experimental lines. There has also 

 been prepared a bulletin on the general subject, which is now 

 in press'. 



With the very efficient aid of S. W. Patterson the study of 

 inbreeding in Jersey cattle has been brought to completion and 

 the results are now being prepared for the press. They give 

 us for the first time a definite, comprehensive, and quantitative 

 idea of the average degree of inbreeding prevailing in a race 

 or breed of domesticated animals, at a particular time in the 

 history of that breed. Because of the novelty and general 

 interest of these results certain of them are here reproduced 

 in Table 5 and Figs- 1-4 inclusive. The derivation and signifi- 

 cance of coefficients of inbreeding have been explained in 

 earlier publications' and need not be repeated here. For rea- 

 sons which cannot be gone into here, but will be in the detailed 

 publications, it is impossible in the case of cattle to arrive at an 

 absolutely exact value of the mean inbreeding coefficients. 

 What we can do is to determine upper and lower limiting 

 values, between which the true, and undeterminable value lies. 

 Such upper and lower limiting values are presented in Table 5. 

 Recalling that the higher the value of a coefficient of inbreeding 

 the more intensely the animal is inbred, we may turn our at- 

 tention to Table 5 and the diagrams. 



'Pearl, R. Further Data on the Measurement of Inbreeding. Me. 

 Agr. Expt. Stat. Bull. 243, 1915. 



°Cf. for example, Pearl, R. The Measurement of the Intensity of 

 Inbreeding. Me. Agr. Expt. Stat. Bull. 215, 1913. 



