(16) 



form characters. This agrees with the conditions found in 

 Table I. There the distinctions between the clones were 

 definite in size and spine characters, but indefinite in 

 form characters. So already two of the characters chosen 

 for study have been practically eliminated for future work. 

 It is perhaps significant that these characters are ratios, 

 a kind of character with which much biorr.etrical work has 

 been concerned. 



In the second place, it is noteworthy that, in every 

 case, the grandparental coefficient is decidedly smaller 

 than the parental. As Pearson (1910) has pointed out, 

 according to the pure line hypothesis the offspring should 

 resemble any other individual of the same clone, for ex- 

 ample, their grandparent, just as much as they do their 

 parent. Pearson's main argument against the evidence of 

 the earlier pure line v;orkers is this phenomenon of the 

 diminishing ancestral correlation, which he considers 

 satisfactory evidence that inheritance of variations within 

 the pure line is occurring. 



Inheritance within single clones. 



Measured by the coefficient of correlation. 



Ancestral correlations in line 30. Because 

 of its rapid rate of division, many more irdii'-iduals of line 

 30 were obtained than of any of the ether races. The fact 

 that this single clone contains 749 individuals makes it 

 much the most suitable for statistical study. The other 

 clones, lines 9, 41 and 43, with 93, 126 and 81 individuals, 

 respectively, will be useful only for comparison. The 



