482 



Journal of Agricultural Research 



Vol. IV, No. 6 



Table 1(A). — Correlation between size of litter in which offspring are born and size of 

 litter in which pairs of parents are born 



f =0.0880 ±0.0070, 

 where r is the correlation coefficient between the sum of numbers in litters in which 

 sire and dam are bom and the number in corresponding litters in which offspring are 

 bom. 



Means of arrays of offspring : 



(i) When sire and dam are singles i. 3452 ±0. 0059. 



(2) When sire is single and dam is twin i. 4171 ±0. 0067. 



(3) When sire is twin and dam is single i. 3946 ±0. 0073. 



(4) When sire is twin and dam is twin i. 4S48±o. 0088. 



(5) When either sire or dam is a triplet i. 6o76±o. 030. 



Mean of all offspring i. 3979 ±0. 0035. 



Table 1(B) simply exhibits percentages of singles, twins, and triplets 

 among offspring that belong to different kinds of parents. It seems 

 from this table that the percentage of twins among offspring of twin 

 parents is greater than that among the offspring of single parents. 

 From the means of arrays of offspring in Table 1(A), we note that the 

 differences are significant when judged by their probable errors. The 

 correlation between the sum of the numbers of lambs born in the litters 

 in which the two parents are born and the number in the litter in which 

 the offspring is born, given by 



r = 0.08S0 ± 0.0070, 

 is a significant positive correlation. 



Table 1(B). — Percentages of offspring born in states I, 2, and j, to correspond to states 

 i-i, 1-2, 2-1, . . . of sire and dam 



° This row of percentages is obtained by grouping together all offspring where either parent is a triplet. 

 Even when thus grouped, the number of offspring is small. 



