An Introduction to a Biology 



FATHERS. 



Dark Pale 



Black. Grey. Grey. Grey. White. Totals. 



Purple. 



. Bluish 

 Purple. 



W 



Purplish 

 Blue. 



Blue 



Pale 

 Blue. 



Totals. 



The degree of correlation in the above Table is that between 

 the number of dice exhibiting 4 or more than 4 points (or " pips ") 

 uppermost in first throws, and the number exhibiting those 

 faces uppermost in second throws, in a series of 300 double 

 throws. The two throws are correlated by leaving half the 

 first throw on the table, so that the second throw has half the 

 dice lying exactly as they fell in the first throw. For details 

 of this process the reader is referred to Weldon :06, p. 100. 



The degree of correlation in my imaginary Table is -54 ; 

 for calculating which I am indebted to Mr. Udny Yule. The 

 " coefficient of parental heredity," therefore, in this case is 

 identical with that for the inheritance of deafness, of which 

 Pearson's Law is true, recently worked out by Schuster (:06, 

 p. 478). Yet, in my imaginary case, none of the children could 

 be mistaken for any of the parents. 



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