SELECTION IN PLANT BREEDING a Ie 
the country, and the individual who was responsible would deserve to be 
ranked among the greatest benefactors of the commonwealth. 
This illustration serves to show something of the extent of the bene- 
fits that may be confidently expected from the improvement of cultt- 
vated plants; but the full extent of our rightful expectations is at least 
ten per cent. increase in both quality and quantity of all the great 
crops of the United States. In fact this is a very conservative forecast 
based upon what has been accomplished in the past. Men like Haynes 
with his “ Blue stem” wheat and J. S. Leaming with his “ Leaming ” 
corn have perhaps made an even greater percentage increase in the 
value of the returns from the land upon which their productions have 
been grown. Their results were obtained largely in the latter half of 
the last century and even greater advances should be made in the fu- 
ture. This statement is made because, in the last quarter of the nine- 
teenth century, experimental biology was in the same relative position 
in which chemistry stood in its beginning. During the century chemis- 
try made wonderful advances; during this—the twentieth—century 
experimental biology will make similar progress. And one of the first 
and most important applications of the facts discovered will be to 
guide and direct man in producing new plants and animals by more 
direct and certain methods. 
When one speaks of producing new plants, however, he should not 
be misunderstood. Man has not yet actually produced new variations 
(although the time may come when even this is possible) ; he simply 
works with the variations which have occurred through natural causes 
of which little is known. The isolation of a varying plant and from it 
the production of a variety, or the combination of desirable characters 
from one strain with other desirable characters from different strains, 
comprises the total aim and desire of the plant breeder. The idea is 
simple; to put the idea into practise successfully is often a tedious and 
difficult task. 
As in hybridization the ease with which results can be obtained by 
selection depends largely upon flower structure. In selection, how- 
ever, the relative facility with which artificial cross-pollination can be 
accomplished is of small importance. What one wishes to know is 
whether cross-pollination or self-pollination takes place naturally. 
Practically all plants are occasionally cross-fertilized naturally, and 
many of them have devices whereby they are nearly always crossed ; but 
we are coming to see that cross-fertilization is not as essential to plant 
life as Darwin endeavored to prove in his “ Cross- and Self-fertilization 
in the Vegetable Kingdom.” Wheat, for example, is almost always 
self-fertilized; yet it has kept its vigor for thousands of years. The 
importance of this fact to the selectionist is easily seen. If seed from 
several varieties of wheat is mixed and planted, each variety remains 
