172 H. H. NEWMAN 



coefficient of correlation for the ten bands is 0.3470 which is 

 very close to expectation especially if we consider that there is 

 an average probable error of ±0.04. 



When one comes to study individual cases he is still more for- 

 cibly impressed by the predominance of the alternative mode of 

 inheritance as opposed to the blending mode. One might take 

 almost any set at random to illustrate this point. In set C 23 

 (table 2, A) for example, we find the following rows with exactly 

 the same numbers of scutes as the mother: 



Fetus I Rings 3, 6, 7, 8, 9, 10 



Fetus II Rings 5, 7, 9 



Fetus III Rings 5, 7, 8, 10 



Fetus IV Rings 1, 2, 3, 5, 7, 8, 9, 10 



In the forty rings of the four fetuses 21 are exactly like the 

 corresponding rings of the mother and 19 are unlike those of the 

 mother and presumably like those of the father. This interpreta- 

 tion of the situation receives a set-back when we note that in 

 ring 1 and also in ring 2 three numbers of scutes appear, of which 

 one is identical with that of the mother. Of course both of the 

 other numbers cannot be identical with those of the father, hence 

 there must be a small amount of blending or striking a compromise 

 between the conditions of the two parents or else there is a certain 

 amount of incomplete dominance. Only two rings out of forty 

 break the rule and we must conclude that the amount of blending, 

 incomplete dominance, is of small and possibly of questionable 

 significance. This set just considered was classed as a mjxed set 

 on the basis of the totals in the ten rings and it shows the admix- 

 ture of the alternative maternal and paternal characters in the 

 individual bands. Let us now examine a set in which there is 

 little or no mixture of the two parental tendencies. Such cases 

 are common enough and we may take as a type set C 30 in which 

 only 2 rings out of 40 are identical with those of the mother. As 

 a type where the maternal influence is predominant we might 

 cite C 90 where 31 out of 40 rings are identical with those of the 

 mother. These are only samples and one can select many other 

 cases equally well illustrating the point. 



