y Swine. 131 



same variety or differences in the percentage of pro- 

 tein or fat in ears of corn. There is no character in 

 any species in which there is not more or less variation 

 and in all cases the variation is sufficient to serve as a 

 basis for vast improvement by breeding. 



Following the universal law of variation there is 

 no doubt that hogs vary in the strength of their breed- 

 ing powers and in the efficiency with which each valu- 

 able character is projected by heredity into future gen- 

 erations. In breeding hogs, as in breeding wheat, dual- 

 purpose cows or business drivers the work must be 

 done on a broad basis. The herd is the financial unit 

 in hogs and to be profitable there must be blended in 

 the male and female individuals all those good qualities 

 necessary to financial success in the herd. While the 

 breeding has often been along too narrow lines in the 

 past many families of this great breed contain the de- 

 sired qualities to a marked degree. 



