294 



THE SMALL GRAINS 



experiments confirmed each other, and demonstrated 

 certain facts: (1) That a change of environment has 

 marked temporary effect upon the plant, but that (2) such 

 effect takes no permanent hold, and is not heritable; 

 (3) that these temporary effects are usually caused by 

 changes of climate; (4) that certain effects in certain in- 

 stances, however, are caused by soil differences ; (5) that 

 no effects upon fundamental characters are produced, 

 such as alterations of form or structure, or physiological 



FIG. 85. Soil exchange plats of Crimean (Turkey) winter wheat at 

 Davis, California; nearest, Maryland soil; middle, California soil; 

 farthest, Kansas soil. 



activity so far as yet determined; that all effects were 

 changes in characters that are fleeting or elastic, such as 

 color and height of plant, tillering, size of head, and color, 

 hardness, and chemical composition of kernel; (6) all 

 soil effects were apparently, because of differences in physi- 

 cal structure of the soil, independent of chemical compo- 

 sition (Fig. 85). 



317. Effect upon protein content. A special aim of 

 these experiments was to determine the environmental 

 effect upon the protein content of the wheat kernel. This 

 effect is sometimes very great, but, as stated, is only 



