14 BULLETIN" 1092, U. S. DEPARTMENT OF AGRICULTURE. 
som Dutch variety, which is 6 inches shorter, but it also has a low 
seed vitality and is inferior to the check in stem length. 
The third group, consisting of Selection Xos. 1904, 1919, 1923, 
and 1931, appears inferior to the check but is analyzed in order to 
make sure that no one of them is worthy of seed increase. Selec- 
tion Xo. 1904 is the most promising one of this group in stem 
weight; it is, however, inferior to the check in stem length, and its 
resistance to wilt is low. Selection Xo. 1919 is very resistant to 
wilt but its stems are coarse ; furthermore, when resistance to disease 
is not considered it grades distinctly lower than the check. Selec- 
tion Xo. 1923 is noticeably inferior to the check in length of stem and 
is not deserA'ing of general distribution ; it is, however, high in stem 
weight in spite of its relatively short stems and may be suited to 
areas where very tall growth is not desired to the exclusion of high 
seed yield. Selection Xo. 1931 is too low in wilt resistance to war- 
rant seed increase and distribution. 
It is concluded from a study of the score card and additional char- 
acters which are not used in the score card that Selection Xo. 1905 is 
the most desirable one for seed increase. Its strength of fiber is not 
surpassed by any selection of which more than one year's record is 
available. It is superior in resistance to wilt to all except two of the 
eleven best selections, and these are undesirable because of coarse 
stems and the extent of basal branching. Out of the five selections 
that are its equal or superior in straw weight, two have a low seed 
vitality, two are inferior in stem length and very low in wilt re- 
sistance, and the remaining selection is more inclined to lodge than 
the check. 
It is recognized that the percentages alloted in this score card are 
more or less arbitrary and that, furthermore, they should be altered 
to suit the convenience of the plant breeder. If, for instance, a 
special attempt is made to select for resistance to lodging, it is 
thought that a much higher percentage should be assigned to that 
factor, so that it would be a determining one in deciding on the best 
selection. 
The chief difficulty in the accurate working of the score card is 
that the systems of planting as well as the places where the sowings 
were made varied widely from year to year ; also, the records on all 
the selections are not complete for the entire 7-year period. Efforts 
are made to overcome these difficulties by comparison with the check 
which is planted each year in many duplicate plats. 
IMPROVEMENT BY CROSS-POLLINATION. 
An attempt has been made, beginning in 1918 and continuing up to 
the present time, to combine the desirable qualities of several of the 
best selections by cross-pollination. Third-generation progenies of 
