l8 MAINE AGRICULTURAL EXPERIMENT STATION. I915. 



These tables show in the two columns to the left of the double 

 ruling the data regarding the selected plants. The four columns 

 on the right show the data regarding the rows which descended 

 from the selected plants. 



By way of example we may note in some detail the data 

 relative to the effect of the 191 1 selection upon the 1912 rows. 

 (Table 3, upper part). First, it is seen that in 1912 there were 

 82 rows grown from plus selections, i. e., from plants whose 

 yield of grain was above the average of their respective pure 

 lines. Likewise there were 74 rows from, minus selections. 

 The 82 plus selections showed a total deviation above the 

 means of their lines of 739.88 grams, or an average plus devia- 

 tion of 9.02 grams per plant. Likewise the 74 minus selections 

 showed a total deviation of 437.97 grams belcrw the respective 

 means, or an average minus deviation of 5.92 grams per plant. 

 In these selections more than one row was frequently grown 

 from the same plant. In such cases the same plant enters into 

 the total deviation as many times as there are rows from it. 



Turning to the second part of the table it is seen that of the 

 82 rows grown from plus selections, 44 showed deviations above 

 the mean of their line and 38 gave deviations in the minus direc- 

 tion. The total deviation of the 44 plus rows was 58.42 grams 

 against 42.53 grams for the 38 minus rows. There is thus a 

 difference of 15.89 grams in favor of the selection. The average 

 deviation per plant for the plus rows is 1.328 grams and for 

 the minus rows 1.119 grams. 



Again, of the 74 rows from the minus selections 33 showed 

 plus deviations and 41 minus deviations. The total plus devia- 

 tions were only 37.62 grams while the total minus deviations 

 were 53.33 grams.'" In the case of these minus selections the 

 average deviation per plant for the plus rows is 1.140 grams 

 and for the minus rows 1.301 grams. 



^"Since for all the rows in any one year the sum of the plus deviations 

 must equal the sum. of the minus deviations it follows that an excess in 

 either direction in the rows from plus selections must be offset by an 

 equal excess in the opposite direction in the minus selections. Thus the 

 difference between 37.62 and 53.33 is 15.71 grams, practically the same as 

 in the case of the plus selections. In most of the distributions these dif- 

 ferences are not exactly equal because the deviations of the rows from 

 their line means were carried to only two places of decimals. The errors 

 are always less than one gram and are neglible. 



