204 DOMESTICATED ANIMALS AND PLANTS 
In these experiments the planting was always made from the 
ears that contained the highest and lowest obtainable proportions 
of oil respectively. The selection may be roughly based on the 
size of the germ, the largest germs having the most oil. 
TEN GENERATIONS OF BREEDING CORN FOR INCREASE AND 
DECREASE OF OIL 
High-oil plot, Low-oil plot, Difference 
average per cent oil average per cent oil between 
Boe In seed In crop In seed In crop eee 
planted harvested planted harvested PSP EE 
1896 4.70 a] 4 4.70 .00 
1897 5-39 473 | 4.03 4.06 -67 
1898 5.2 5.15 3-65 3-99 1.16 
1899 6.15 5.64 SA 3-82 1.82 
1909) 6.30 6.12 B33 3-57 2:55 
I9OI 6.77 6.09 2.93 343 2.66 
1902 6.95 6.41 3-00 3.02 3-39 
1903 6.73 6.50 2.62 2.97 3-53 
1904 7-16 6.97 2.80 2.89 4.08 
1905 7.88 7-29 2.67 2.58 Re 
1906 7.56 7:37 2.20 2.66 4.71 
Exercises. Study and report upon any plant-breeding operations of the 
neighborhood, especially with reference to the following points: what im- 
provements are sought ; how seeds are selected, and on what points selection 
is based; how stored for the winter: how planted, and what records are kept. 
Plant in separate rows ten of the best ears of corn obtainable, describe 
and number each ear, and give the same number to the row in which it is 
planted. Then make a careful study of the crop, both as to yield and uni- 
formity, using the statistical methods for determining variability. 
Plant separately from the tips, the middle, and the butts of the same ears 
of corn. Next year select a set in the same way from the respective crops, 
and continue the experiment for a series of years in order to get the cumu- 
lative effect of the late small kernels at the tip as compared with the early 
and large kernels of the base. Do not look for too much difference the 
first year. ; 
Bring to the school garden any field crop or garden plant in which there 
is general interest, and begin work, looking to its improvement. 
