34 MISCELLANEOUS PAPERS. 
close-fertilized plants like wheat they are entirely inapplicable to a 
cross-fertilized plant like corn. 
The popularization of the new theories has continued until they 
are now not only urged as a basis for scientific experiments in breed- 
ing, but are even recommended as a guide for the practical farmer. 
It is assumed that uniformity is a normal condition. New “ ele- 
mentary species ” are supposed to originate by sudden changes and 
then to remain uniform, so that no further change is possible after 
a “pure strain” has been isolated, until new mutations occur. If 
these theories were correct, then it would be true, as De Vries main- 
tains, that the breeder is wasting time in attempting to ameliorate 
varieties by the continued selection of minute variations after the 
elementary species have been isolated. 
The hundreds of improved forms of domesticated plants which 
have been derived and maintained by continuous selection through 
long periods of time sufficiently refute the claim that selection is 
ineffective and should warn breeders from the danger of abandoning 
too soon a system which has yielded such brilliant results. As 
apphed to corn the De Vriesian doctrine is particularly dangerous, 
since 1t would replace the already close selection by a method of still 
narrower breeding, the nearest approach to self-fertilization that is 
possible with a cross-pollinated plant. 
Independent of these theories, many corn breeders have been aim- 
ing at uniformity, and such will doubtless welcome this apparent 
justification. It is perhaps fortunate for the progress of corn breed- 
ing that the wide promulgation of these theories has been delayed 
until the fallacy of the system of close breeding is beginning to be 
appreciated and the more thoughtful and observant of our corn breed- 
ers are viewing with distrust the system of close selection and are 
casting about for an alternative method. 
DEVELOPMENT OF THE PRESENT METHODS OF CORN BREEDING. 
Stated broadly, the object of breeding field corn is to produce 
varieties that will give the largest yield of grain under given condi- 
tions. The latitude allowed by this simple object gives the corn 
breeder an advantage over the breeder of more specialized crops— 
an advantage which has not been fully appreciated. The varieties 
of sweet corn fall more nearly in the class with vegetables, and the 
many special requirements, such as taste, appearance, and uniformity 
make their improvement a much more complicated and very different 
problem from that of the improvement of field corn. With field 
corn the development of varieties with special qualities will not 
become an important consideration until the possibilities of corn as a 
human food are much more fully appreciated than at present. 
Is —i\y 
