60 CORN 



CONSTITUTION. This term is often confused with vitality. A 

 plant or animal may have vitality, that is, there may be life present, 

 but it may lack strength and vigor. Many corn plants that come 

 through the ground in the spring never attain any size. 



In-breeding in corn tends, as in live stock, to weaken the constitu- 

 tion of the plants. The blades become narrow and of a light green 

 color, the root system shallower and the stalk itself more slender. The 

 weakness is often inherited, although it may result from improper 

 care of the seed. The offspring of an ear of corn or spike of wheat 

 may, from germination to maturity, show certain characters of 

 strength which stand out distinctly. The breeder takes advantage of 

 this fact, especially in the production of plants of economic impor- 

 tance. New varieties are evolved in this manner. The importance 

 of knowing the ancestry of one of these plants with marked constitu- 

 tion cannot be overestimated. The environment has much to do with 

 the highest development of virile characters. 



WATER, The presence of water in a plant is necessary for tlae 

 activity of its cells. The protoplasm, which is the mo.st important 

 part of the cell, is a more or less slimy or jelly-like substance contam- 

 ing a considerable proportion of water. The peculiar phenomenon 

 which is called "life," is associated with this watery substance. The 

 amount present is influenced by the kind of plant and the environ- 

 ment. Fresh red clover hay contains 70 per .cent of water; green tim- 

 othy hay, 62 per cent; mangel beet roots, 91 per cent; potatoes, 79 

 per cent; corn silage, 79 per cent; corn from the crib, 11 per cent. 



THE ABSORPTION OF WATER, The adequate absorption of 

 water goes on only when the following conditions are present : 



(1) A degree of temperature suitable to the nature of the plant. 

 The oat plant will absorb moisture from a much colder soil than will 

 the corn plant. The millets require an even higher temperature. A 

 corn plant is slow to use moisture early in the spring, although 

 requiring a great deal for the most rapid growth during the summer 

 months. Well water poured into pots of tropical plants in a green- 

 house often checks their growth. 



(2) A supply of fresh air. Imperfect respiration occurs in the 

 roots of plants which are growing in soil which is so full of moisture 

 as to exclude oxygen. Undrained portions of corn fields, where the 

 water stands on the surface or very near it, always grow weakly 

 stalks. Even in July, when this water is warmed, the plant cannot 

 use it because of the exclusion of air. 



