90 



Clyde E. Leighty 



the means for all characters are greater for the individual culms than for 

 the average per culm of plant. It may be concluded, then, that for 

 statistical work with oats practically the same means for the different 

 characters will be obtained whether the plants are used as units — the 



TABLE 2. Correlations, Series 1221 and 22. Plants or Culms as Units 



Series 1221 



Series 22 



Average yield of culm per plant, in decigrams — 

 Average height of plant, in centimeters 

 r= .853 ± .011 



Total yield of culm, in decigrams — 

 Total height of culm, in centimeters 

 r= .854 ± .006 



Average yield of culm per plant, in decigrams — 

 Average number of kernels per culm of plant 

 r= .952 ± ,004 



Total yield of culm, in decigrams — 

 Total number of kernels per culm 

 r= .957 ± .002 



Average yield of culm per plant, in decigrams — 

 Average number of spikelets per culm of plant 

 r= .931 ± .005 



Total yield of culm, in decigrams — 

 Total number of spikelets per culm 

 r=: .938 d= .003 



Average yield of culm per plant, in decigrams 

 Average weight of straw per culm of plant, in 

 decigrams 



r= .856± .010 



Total yield of culm, in decigrams — 



Total weight of straw per culm, in decigrams 



r= .872 ± .006 



Average yield of culm per plant, in decigrams — 

 Average weight of kernels per plant, in milli- 

 grams 



r= .493± .029 



Total yield of culm, in decigrams — 

 Average weight of kernels per culm, ip milli- 

 grams 



r= .573 ± .015 



Average weight of kernels per plant, in milli- 

 grams — 

 Average height of plant, in centimeters 

 r= .325 ± .035 



Average weight of kernels per culm, in milli- 

 grams — 

 Total height of culm, in centimeters 

 r= .431 ± .019 



Average weight of kernels per plant, in milli- 

 grams : — 

 Average number of kernels per culm of plant 

 r= .250 ± .036 



Average weight of kernels per culm, in milli- 

 grams — 

 Total number of kernels per culm 

 r= .380 ± .020 



average per culm being here determined — or the culms of the same 

 plants are used as units; but that the means will generally be slightly 

 greater for the culms as units. 



The measures of variation, however — the standard deviations and the 

 coefficients of variability — both indicate, consistently throughout, a 



