The ram C-1659 is the sire of more outstanding winners at the International Livestock Exposition from 1913 to 1938 than any other ram. Blendworth Herriard 45215, the sire of C-1659, is the most important sire of ewes the dams of winners at the same show. Concentrations in varying proportions of the blood of these two rams and other sons and grandsons of Goldmine, have produced more important winning sheep than any other blood or families used in the United States. As far as the age of either parent is concerned with Hampshire sheep, the offspring born at one age is no more apt to be a winner than the offspring born at another. A good breeding individual was apt to be so from the beginning. However, ewes for example, may respond very differently to two rams of unlike breeding as far as quality of offspring is concerned. Rams may differ in their ability to transmit desirable characteristics to their offspring on the basis of sex of the offspring. Some may sire better ewes, while some may sire rams of superior quality. This work suggests that there may be a 1:3:1 ratio among outstanding rams so that of five sires randomly selected, one would sire superior ewes, one superior rams, and three could do both equally well. / Master of Science