PLANT FOOD AND GROWTH. 27 



The seeds each contain a very small plant called 

 the germ or embryo; also a quantity of plant food, 

 enclosed in a coat or outer covering. The germ or 

 little plant is readily examined in such seeds as corn or 

 peas, if these are soaked in water until they begin to 

 swell. 



The matter surrounding the germ contains all 

 the food needed to support the little plant when it 

 commences to grow, except oxygen and water. The 

 principal content of most seeds is starch; of some, as 

 flax, fat. There is also nitrogenous or albuminous 

 matter, and all the ash ingredients needed by the plant. 

 The young plant is fed and nourished by the food 

 stored up in the seed much as the embryo chick is 

 nourished by the store of food in the egg. 



Oermination and Growth. — Germination of 

 the plant, or growth of the germ in the seed, 

 commences when there is a suitable temperature 

 and a sufficient supply of moisture and oxygen. 

 Warmth, moisture and air, or oxygen from the air, 

 are essential to the growth of any plant. These sup- 

 plied the growth of any perfect seed will certainly 

 commence. Under like conditions the growth of the 

 "eye" or bud in a potato or other tuber will com- 

 mence. 



The seed first swells; the solid matter becomes 

 soluble; the starch or fat is changed into a form of 

 sugar; the germ sends out a root called the "radicle," 

 and the leaf called the "plumule." If the seed is sur- 

 rounded by soil in suitable condition the radicle soon 

 begins to absorb food from the soil. The plumule ex- 

 tends upward until it reaches the surface, when the 

 leaves more fully develop and begin their work. 



