Sept. IS. 191S Resemblance of Parents and Offspring of Sheep 503 



Table XXVI(A). — Correlation between offspring and sires with "complete American " 



pedigree 



r=o.o72±o.oii 

 Means of arrays: 



(i) When sires are singles i. 3578±o. 0072. 



(2) When sires are twins i. 4224±o. 0093. 



(3) When sires are triplets i. 700 ±0. 095. 



Table XXVI(B). — Percentages of offspring in states I, 2, and j to correspond to the 

 states I, 2, and j of the sires with " complete American " pedigree 



All our results with index numbers show consistently a larger relative 

 production of twins by twin sires than by single sires. It may be noted, 

 however, that in the case of the subclass remaining after those of "complete 

 American" pedigree are removed, the difference is not three times its 

 probable error. This surely means that it requires very large numbers to 

 establish with any considerable certainty the significance of the difiference. 



TABLES FOR SIRES AND PATERNAL GRANDPARENTS 



Tables XXVII to XXX for "complete American " pedigrees correspond 

 to Tables X to XIII for the total population. Here again, as with the 

 total population, we are unable to assert the existence of a significant 

 correlation between paternal grandparents and offspring with respect to 

 being born in singles or in twins. 



