146 



Pearl and Surface. 



Table 



Series 



Showing the mean quintile position and standard 



ing to mean 



Mean qnin- 



The mean qnintile position and its standard deviation measure 

 definite characteristics of a plant. The constants give at a glance a 

 large amount of information about the growth of any particular plant. 

 Thus the mean quintile position of a plant tells whether, for the season 

 as a whole, the plant has been relatively large or small or medium. 

 Further, the standard deviation tells whether the plant has maintained 

 this relative size throughout the season or whether it has fluctuated 

 from one relative size to another. These are important quantitative 

 characters of a plant. We hope to show that these characters are of 

 a fundamental importance for the analysis of growth and particularly 

 for the relation of growth to underl.ying genetic factors. For this 

 reason these characters will be discussed in detail in the following pages. 



