No. 598] SHORTER ARTICLES AND DISCUSSION 



635 



Or for the dams and grandams : 



When dams and grandams are singles 1.3446 ± 0.0057 



When the dams are twins and grandams are singles 1.4245 ± 0.0071 



When the dams are twins and grandams are twins 1.4559 ± 0.0078 



When either dam or grandam is a triplet 1.545 ± 0.037 



Finally for the maternal grandams alone : 



When the maternal grandams are twins 1.4120 ± 0.0052 



When the maternal grandams are triplets 1.556 ± 0.033 



It is quite out of the question to review in any detail tlx' 

 thorough analysis of the numerous interrelationships deduced 

 from the many thousands of records abstracted by the authors 

 from the Shropshire record. Their data seem to be free from 

 the possible objection raised against the swine records above, for 

 the correlation between sire and dam. which may be deduced 

 from their Table I, is only r = .0058 ± .0070. 



The intensity of correlation between the size of litter in which 

 an individual is born and the size of the litter in which his sire 

 or dam or grandsire or grandam was born is very low. The 

 maximum relationships are in fact of the order r=.08. 



In the parental relationships the correlation between the size 

 of litter in which the sire was born and the size of the litter in 

 which his offspring were born seems to be significant, as well as 

 that between the size of the litter in which the dam was born and 

 the number of the offspring. The mean number of offspring 



Note the agreement of this result with that obtained by W 

 worth and Aubel. An explanation on the basis of identical t 



