FARM ANIMALS 



sodium nor chlorine can be divided into two or more 

 substances, and hence each is a fixed unit or sub- 

 stance, known by the term element. 



Of the 81 elements to be found in the world only 

 12 enter in the life of plants and animals. These 12 

 are very important because they are positively 



necessary to 

 plants or animals. 

 They are the very 

 basis of life. The 

 body of the ani- 

 mal is composed 

 of the elements 

 found in plants, 

 yet the plant must 

 grow in order to 

 make it possible 

 for the animal to 

 grow. From the 

 air and the soil 

 our cultivated 

 plants gather the 

 chemical elements 

 together, and with them build plant tissue. By 

 means of roots, the soil is searched in every direc- 

 tion for soluble plant food, and this is drawn into 

 the plant. The leaves in the air, also at work, entice 

 into their being the floating carbon which, trapped 

 and held, is mixed, as it were, by means of cellular 

 life with the soil elements that have been carried 

 into the plant in the soil water. As a result com- 

 pounds are formed, the cells enlarge and increase, 



CROSS SECTION OF ROOT HAIR 

 Soluble plant food is carried into the plant 

 through root hairs. These are very small. 

 The part pictured here is greatly magnified. 



