CORN. 213 
son for other points by allowing for differences in tempera- 
ture and moisture. Seed corn, more than all other crops, is 
directly dependent on the total amount of heat and sunshine 
during thesummer. The latitude north or south increases 
or decreases this total heat and directly modifies the kind of 
corn itis possible to grow. Corn needs a dry air and sun- 
shine. The presence of much moisture due to swamps and 
woods or the nearness of large lakes like Superior, with fog, 
retards its growth. There is a theoreical standard of pro- 
duction for each locality, representing the largest and the 
best corn that can be depended on to ripen annually at that 
point. All smaller and earlier kinds than this will not pro- 
duce as much, and largerand later kinds will not ripen. This 
standard shifts with the locality and makes it difficult to 
breed varieties of corn in one place which will be the best 
kinds for other and different localities. It accounts for the 
failure of corn, which does well at one point, to ripen at an- 
other. But districts as they become better developed, have 
uniformly improved the kinds of corn raised, as every one 
knows. This is due first to the reduction of the excessive 
moisture in the air and soil, by drainage and clearing, and 
secondly, to selection and improvement of the corn itself. 
These indisputable facts are often quoted to prove that 
northern Minnesota will in time grow as good cornas Iowa. 
This loses sight of the influences of latitude which will for- 
ever confine corn growing within certain limits, beyond 
which local modifications cannot pass. From the facts at 
hand, it is safe to prophesy that in the latitude of Grand 
Rapids dent corn of reasonable size may sometime be grown 
with perfect safety, but it will always be smaller and less 
productive than that grown from Princeton south. In test- 
ing varieties, the standard kinds have been obtained from 
seedsmen, and in addition, as many strains as possible from 
farmers at various points in the northeasern counties. Of 
the twenty-five flints tested, table CV gives the results ob- 
tained with eight standard kinds in an average of between 
four and seven years trial with each variety. 
