1916] PRITCHARD—SUGAR-BEET BREEDING 431 
The average variability of the roots as shown by the standard 
deviations was 1.2 5-I.59 per cent sugar and 19. 28-37.99 grams 
of sugar. Measured by the coefficient of variability, this amounts 
to 6-12 per cent of the mean for percentage of sugar and 18-50 
per cent for quantity of sugar, which are fairly large differences for 
averages. 
TABLE I 
VARIABILITY OF SUGAR-BEET ROOTS IN PERCENTAGE AND QUANTITY OF SUGAR 
Station Yer SS oe Mean Standard deviation| Coefficient of 
Percentage of sugar in roots 
Fairfield: boee. 1907 230 20.150.056 | 1.260.039 6.25 
eo hee I 400 20.374+0.048 1.470.035 > a2 
wees Igo 400 17.340.044 | 1.310.031 7.55 
i Igto 60.042 | 1.250.029 6.66 
Brookings... . IQII 3784 17.67%0.017 | 1.590.012 8.90 
Madison eG 1g12 500 12.8640.047 | 1.550.033 12.06 
(Cave: 1913 500 4.240.041 | 1.350.029 9.46 
Quantity of sugar per root in grams 
LE nine ANGE lig sre 
Madison Mees Igi2 500 98.46+1.146 | 37.990. 810 38.58 
ee es 1913 500 54.020,807 | 26.760.570 49.53 
Fairfield oe Igto 126 104.611.191 | 19.850.850 18.97 
Ee ere. Igto 147 104.90+1,.077 | 19.28%0.770 18.38 
yp ottteee 1909 231 113.68*1.134 | 25.439. 790 22.37 
Brookings... . . IQII 3784 79.870, 206 | 23.9420. 186 29.97 
ee ee 
The range of variation for percentage of sugar in individual 
beets is not shown in table I, but varies ordinarily from about 
8 to 24. Small, immature beets frequently contain less than 8 
per cent sugar, and occasionally a root is found which contains 
more than 24 per cent. We found one beet at Madison which 
showed 26 per cent sugar in 2 separate analyses. Another small 
Toot, so small in fact that it had to be bored lengthwise through the 
center to obtain a sample of pulp, contained 30 per cent sugar. 
RELATIONSHIPS BETWEEN A FEW COMMONLY DETERMINED 
CHARACTERS OF THE ROOT AND ITS YIELD OF SEED.—A knowledge 
of the relationship of such characters as root weight and percentage 
of sugar to seed production is essential to intelligent selection. Very 
