THE PEED PROBLEM 251 



The hydrogen and oxygen may be taken up in the form of 

 water (H2O). Half -grown clover has been found to contain 

 as much as 90 per cent, water. The water taken up through 

 the roots carrying mineral matter and other plant nutrients 

 in solution is known as sap, and flows from the roots to the 

 leaves, where the excess is given off as watery vapor. Analysis 

 and study has shown that wheat, beans, and clover may exhale 

 two hundred times their dry weight of water during five 

 months of their growth. 



Carbon dioxid (CO2) is taken in through minute openings 

 in the leaves. Through the decomposition of the water and 

 carbon dioxid and a rearrangement of their elements in the 

 plant, starch is formed with an excess of oxygen which is 

 exhaled through the leaves. Thus, the plant utilizes carbon 

 dioxid, a poisonous gas given off from the lungs of animals, and 

 gives off in return oxygen, which oxygen is necessary for the 

 support of animal life. It may be said, therefore, that plants 

 support animal life and that animal hfe supports plant life. 

 This starch is the foundation of one of the principal groups of 

 food nutrients needed in poultry feeding — namely, the carbo- 

 hydrates. One molecule of starch may be converted into a 

 molecule of cane-sugar by the addition of a molecule of water, 

 thus: 



C12H20O10 + H2O = C12H22O11 



starch. Water. Cane-sugar. 



Cane-sugar may be converted into glucose, another form of 

 sugar, by the addition of another molecule of water, thus: 



C12H22O11 -t- H2O = C12H24O12 



Cane-sugar. Water. Glucose. 



Therefore, sugars and starches form the carbohydrate group. 

 It is noted that in the carbohydrates the hydrogen is always 

 twice the quantity of oxygen content. 



A molecule is composed of atoms. A molecule of starch is 

 made up of 42 atoms — that is, 12 atoms of carbon (Ci2),20 

 atoms of hydrogen (H20), and 10 atoms of oxygen (Oio). By 

 the addition of 2 atoms of hydrogen and 1 atom of oxygen 

 the starch is converted into cane-sugar, as illustrated above. 



Fats and oils form another plant material and which con- 

 tains the same elements that compose starch — namely, carbon 



