60 UNIVERSITY OF ILLINOIS 



growing season of spring does not form grain, nor does it produce 

 well when sown in the fall if the winter be without cold weather. 

 Spring wheat, when sown late, may make as much growth of straw 

 as does that sown early but it does not produce as much grain in pro- 

 portion as does the early sown. Hardy trees and shrubs do not grow 

 so well in the spring after being kept from frost during the winter as 

 they do after they have endured normal outside conditions. What 

 are the problems involved in these changes, and is there any application 

 to be made to any extent to such other crops as corn, oats, etc. ? 



Each grain or seed is a product of parental mating, and with 

 plants the same laws prevail as in the mating of animals. We have 

 studied the succession of visible characters under the laws supposed to 

 govern ; but has any attention been given to mating to secure those 

 invisible characters if they are invisible on which depend such 

 things as longevity, the inherent tendency to overcome adversity, to 

 resist diseases, and to show strength in development in the face of 

 adverse environment? Should we not study plants with reference 

 to their vitativeness, if in doing so we may find some of the factors of 

 immunity to diseases of many kinds? 



