PLANT. BREEDING 311 
portant results that have been attained by plant breeders 
by means of the process of continued selection outlined -in 
Sect. 890. In a general way it may be said that almost 
any characteristic of a plant or of one of its organs may 
be made to vary, often in any desired direction. Flowers 
or fruits may be caused to increase in size many times 
over; early or late blooming or fruiting may be secured; 
greater resistance to frost, drought, insects, or parasitic 
fungi may be developed; a larger per cent of starch, sugar, 
or oil in given parts of the plant may be obtained: at 
will. Some instances of such modifications are given in 
succeeding sections of this chapter, but works on farm- 
ing and horticulture contain thousands of examples of 
the sort. 
392. Sugar-Beet Breeding. — Although we are more 
familiar in this country with sugar made from the sugar- 
cane, the larger part of the world’s supply is manufactured 
from sugar-beets. Beets of many varieties have been cul- 
tivated since the sixteenth century or earlier. But it was 
only as late as the middle of the nineteenth century that 
scientific efforts were made by Louis Vilmorin to increase 
the percentage of sugar in beets grown for sugar-making. 
The sweetest roots are usually the heaviest in proportion 
to their bulk,! and therefore Vilmorin tested whole beets 
or pieces cut from them by placing them in brine strong 
enough to float all of the roots except those which con- 
tained an unusually large per cent of sugar. These selected 
beets were planted for seed and became the parents of valu- 
able new races. 
At present the process of producing beets of the high- 
. est value for the manufacture of sugar is a long and 
1 That is, have the highest specific gravity. 
