430 BOTANICAL GAZETTE [DECEMBER 
dividing each class by the total number of variates in the popula- 
tion; hence the graphs are comparable. 
Fig. 1 shows the superiority of Madison Original Selections 
over Morrison’s Kleinwanzleben at Madison, where the percentage 
of sugar is normally low and a higher percentage is the chief desid- 
eratum. Hence the foreign varieties from which the Madison 
Original Selections were made are better as foundation stock at 
Madison than the variety Morrison’s Kleinwanzleben. One or 
two plantings of each variety would hardly suffice to show this 
difference, but the large number of replications used were sufficient 
to establish it with a fair degree of certainty 
Morrison’s Kleinwanzleben has been selected for a high yield 
of sugar, and in tests with foreign varieties in several different local- 
ities in the United States it has usually stood preeminent in this ~ 
respect. Ina 5 years’ test at Fairfield, Washington, where it was 
bred for to years, it was equal to Kleinwanzleben’s Original and 
better than 11 other varieties in percentage of sugar and ranked 
first in yield of sugar. At Madison, however, it is not well adapted 
to the breeders’ needs as foundation stock. Although it was 
superior to Kleinwanzleben’s Original in yield of sugar in 1913 
(cf. fig. 30), it was inferior to it in 1912. It was relatively low in 
percentage of sugar in comparison to the checks (K WO) in 1912, 
and continued to maintain this position in its second year’s test 
after all the supposedly poor families had been eliminated. 
ELECTION OF MOTHER ROOTS.—The selection of mother roots 
for the purpose of starting a new family of beets or improving 
one already established is usually made upon the basis of size, 
shape, percentage of sugar, and relative freedom from mineral 
substances which interfere with the extraction of sugar. The 
coefficient of purity is not usually determined for breeding purposes, 
however, as only roots containing a high percentage of sugar are 
_ saved and they are almost invariably characterized by high purity. 
As size and shape are distinguished by physical selection, percent- 
age of sugar is the only character determined chemically. 
VARIABILITY OF MATERIAL FROM WHICH MOTHER ROOTS WERE 
SELECTED.—The variability of beet roots in percentage and quantity 
of sugar is ample for selection, as may be seen in table I. 
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