CORN BREEDING 57 
tion or in combination. As a result of these experiments it is highly 
probable that crosses between selfed lines will be found that can be 
utilized to produce larger acre yields of corn in the different States. 
It is not improbable that other methods for utilizing selfed lines 
that are being tried now or that may suggest themselves later will 
be found more practical for commercial utilization than crosses or 
double crosses. In any event it will be some time before even high- 
yielding single crosses are available for most sections of the United 
States. At least three or four years of self-fertilizing are necessary 
before crosses can be made for preliminary testing, which requires 
another year. Another season is used in recrossing the lines indi- 
cated as promising by the preliminary trial in order to obtain seed 
for a more thorough comparison. It consequently requires six or 
seven years to locate the few better crosses that are worthy of more 
extensive comparison under more nearly practical conditions. Even 
more time is needed if double crosses or synthetic varieties are to be 
found. It evidently will be some time, therefore, before these prod- 
ucts of the newer methods of corn breeding can come into anything 
like general use. 
It is advisable to insert a word of caution as to buying crossed 
seed corn. The large yields that have been obtained experimentally 
from some crosses are likely to create a demand for crossed seed 
before it can be supplied in any considerable quantity. This will 
make it possible to obtain a large price for the supplies that do exist. 
There is no objection to a reasonably high price for seed corn that 
will yield 10 to 15 bushels per acre more than the best present varie- 
ties. One bushel of such seed will increase the income about $30 
to $45, assuming that it will plant 6 acres and that com is worth 50 
cents a bushel. Unfortunately, there are likely to be many individ- 
uals who will offer to sell crossed seed at a large price when the seed 
is little, if any, more productive than ordinary seed corn. Either 
the absolute honesty of the one offering crossed seed for sale must 
be known to the buyer or the latter must realize that he is taking 
chances of being defrauded. The greatest danger from fraud of this 
kind will exist before crossed seed is available generally through the 
ordinary channels. Methods of seed inspection and certification pre- 
sumably will be developed later that will restrict effectually the 
opportunities for dishonesty. In the meantime farmers should be 
particularly cautious about buying seed for which extravagant claims 
are made by people of unknown standing. 
Furthermore, it should be recognized that adaptation is just as 
important a factor in determining the yield of crosses as it is in 
determining the yield of varieties. That a cross is unusually pro- 
ductive in one section is no evidence that it can be grown profitably 
in another locality with a different environment. Consequently if a 
farmer wishes to buy seed of a cross because it has yielded unusually 
well elsewhere he should buy only a small quantity at first and recog- 
nize that it is an experiment. If planted on a large scale he may 
lose considerably either by the cross yielding poorly under his condi- 
tions or by its failing to mature properly, or by both. 
In conclusion, it may be said that selection within selfed lines 
unquestionably offers opportunities for obtaining materially larger 
acre yields of corn, Methods involving this principle are primarily 
