CHAPTER XIII 

 THE RELATION OF THE PLANT TO WATER 



Water Content. — The living plant contains a vesry high per- 

 centage of water which can be readily determined by weighing 

 the fresh plant, drying it thoroughly in an oven and then weigh- 

 ing a second time. The amount of water varies greatly in dif- 

 ferent plants and also in different parts of the same plant The 

 soft, succulent plants, the fleshy parts of many plants, and the 

 fruits of many plants contain high percentages of water as com- 

 pared with the hard and woody parts of plants and the mature 

 seeds and grains. In fact, most of our vegetable foods are made 

 up almost entirely of water. The following table will give some 

 idea of this great variation of water content : 



Plant Percentage of Water 



Cucumber, fruit 96.00 



Beets, roots of mangel-wurzels 90.00 



Cabbage heads 90.00 



Beets, red 88.00 



Sugar beets 86.50 



Cow peas, hay, green 83.60 



Corn fodder, green 79.08 



Potatoes, Irish 78.90 



Potatoes, sweet 71.10 



Rice, grain 12.60 



Oats, grain 1 1.00 



Corn, grain 10.90 



It will be readily seen that the water content iu different 

 parts of a plant varies ; the ripe fruit of the tomato will cer- 

 tainly contain more water than the stem and leaves. The ripe 



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