1910.] 



PUBLIC DOCUMENT — No. 31. 



169 



Differences in Variability. 

 As was shown in our last report, there are great differences in 

 variability to be seen in different strains, even within the same 

 variety. The progeny of nine different parents, all belonging 

 to the same variety, was compared in this respect. These same 

 strains may now be compared again, bringing into comparison 

 the progeny grown in another year's crop. In the following 

 table CV stands for " coefficient of variability," which is simply 

 a mathematical function showing the relative variability of the 

 various strains. It is secured by dividing the standard deviation 

 by the mean. The larger the figure the greater the variability 

 indicated. 



