i879-] 
557 
Seed- Breeding, 
Thus, through selection, winter and spring wheat, which 
botanically have been considered distinct species, have been 
transformed the one into the other. The beet-sugar plant, 
since its introduction into cultivation for sugar in France, 
has had its percentage of sugar almost exactly doubled 
through the agency of most careful selection and testing of 
roots gathered to be used for the growing of seed. By selec- 
tion during a course of years the early maturity of peas in 
Great Britain has been hastened from ten to twenty-one days. 
Among florists’ plants the Canterbury bell was doubled by 
four generations of selection. The wild cabbage plant has 
been developed into at least ten distinct varieties through 
cultivation ; the crab has been transformed into the apple ; 
the sloe into the plum ; the wild grape into the concord 
grape ; the wild strawberry into the large and fine cultivated 
species, and each year brings numerous varieties thus 
gained before the purchasing public. The whole secret of 
all these triumphs being the production of or the seeking for 
variation, and then putting into aCtion a rigorous selection. 
How rapidly changes may take place in a plant through 
yearly variation is shown by the results of Metzger’s growing 
of corn in Germany from foreign seed. In the third gene- 
ration, in one case, nearly all resemblance to the original 
and very distinct parent form was lost, and in the sixth 
generation this maize perfectly resembled a European 
variety. In another case, with a “ white-tooth corn,” the 
tooth nearly disappeared in the second generation. In our 
own experience we find that various features of the corn 
plant resist aCts of selection more strongly than do others. 
It has seemed to us that three generations of selection have 
sufficed to change the size of the cob and the shape of the 
cob; that it has had a strong influence in changing the 
character of the grain, but has not yet fixed it ; and that it 
has had a less effeCt on the earing habit of the plant, and 
yet an effeCt which is very noticeable and persistent. 
Let us now consider the corn plant alone, and see what 
features we desire to obtain, and what must be the principle 
of selection which would seem the most efficient to bring us 
success. 
As a rule, the one feature of the plant that concerns the 
farmer the most is that of prolificacy. There is less differ- 
ence betweeen the values of different qualities of corn grain, 
from a sale point of view, than there is between the yield of 
different varieties. Seventy-five bushels per acre of any 
variety grown is usually more valuable than forty bushels of 
another variety, and yet these figures represent aCtual dif- 
