A COMPARISON OF MAIZE-BREEDING METHODS 19 
The experiment was planned to test the possible value of elimi- 
nating inferior strains from a commercial variety by means of selfing; 
and the answer, so far as it is given by this experiment, is that the 
method is of doubtful value. 
There is strong though rather indirect evidence that, in the course 
of the selfed experiment, a single superior strain was isolated that 
i918 i919 i920 192! IS$22 1923 1922. 
——— 5 ee aa oe Vig 
AE ooo Ss J ‘s 
ee 
Sit te. ea 
Ne RS AS eRe SOR Ay 
ee AZZ: 
SN es Re Se et rN 
OR Se me eee at NS NaS 
“9 ZO 
Fic. 7.—Descent of progenies of maize in the selfed experiment. Each year the progenies are numbered 
according to their standing as determined by the average length of ear. The dotted line incloses the 
descendants of progeny No. 1, 1921 
produces high-yielding progenies when combined with other strains. 
Whether this strain can be made agriculturally useful remains to be 
determined. The unique behavior of this progeny makes it unwise 
to attempt generalizations. There is no way of telling from the 
| present experiment with what frequency the occurrence of similar 
superior strains is to be expected. 
