5o6 



Journal of Agricultural Research 



Vol. IV, No. 6 



ANALYSIS OF DATA ON PARENTS AND OFFSPRING SEPARATED WITH 



REGARD TO SEX 



Table XXXI exhibits data for the correlation of size of litters in which 

 sires are born and sizes of litters in which their female offspring are bom. 

 The importance of investigating the tendency of twin sires to produce a 

 larger percentage of twins armong female offspring than single sires pro- 

 duce among female offspring is suggested by the fact that, from the data 

 of Tables VIII and XXV, we were unable to assert the existence of a 

 significant correlation. 



Table XXXI(A). — Correlation between female offspring and sires 



r^^.04io±o.ooS6. 

 Means: 



For sires i. 3987 ±0. 0044. 



For female offspring i. 388o±o. 0043. 



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

 states I, 2, and j of the sires 



From Table XXXI (A) we obtain for the correlation 



r = 0.0410 ±0.0086. 



While this is a very small correlation, it is 4.6 times its probable error. 

 While it is by no means finally established, it seems somewhat more 

 probable that the values in Tables VIII and XXV are accidentally small 

 under random sampling than that the correlation just given is insignificant. 

 What is clear is that if any correlation exists, such correlation is so small 

 that it requires immense numbers to establish its significance. 



