Orowth and variation in maize. 



159 



It would be possible to determine the standard deviation of each 

 of these distributions and the average of these for each class could be 

 compared with the average standard deviation given in table 18. Since 

 there are several thousand possible combinations this would involve a 

 great amount of work. It will be simpler to sum all the distributions 

 in a given class and then obtain the standard deviations from these 

 total distributions. 



Table 19 gives the total number of possible observations falling 

 in each quintile, distributed with respect to the classes of mean quintile 

 position. The mean and standard deviation of each distribution is also 

 given. 



Table 19. 

 Showing the quintile distribution of the total number of pos- 

 sible observations in all the separate combinations of four- 

 teen observations of which the individual mean would fall 

 within the class given at the left of the table. 



In order to obtain constants which are comparable with these 

 means and standard deviations it will be necessary to go back to the 

 quintile distributions of the individual plants and obtain the total 

 frequency on each quintile for plants having their mean quintile positions 

 in the same class. The distributions of the individual plants and the 

 totals for each class are given in tables 61, 62 and 63. 



The means and standard deviations of each of these total distri- 

 butions may be obtained and compared with the theoretical constants 

 from table 19. The means and standard deviations for each series to- 

 gether with the theoretical constants taken from tables 19 are given in 

 table 20. 



