EXERCISE 2. WHERE THE PLANT OBTAINS ITS FIRST 



FOOD 



Equipment: Two small tin cans filled with sandy soil; 

 a few beans; some grains of corn. 



Method: (1) Plant two beans in the can of sandy 

 soil and keep the soil warm and moist. As soon as the 

 leaves appear above the, surface of the soil, carefully remove 

 the two half beans, or cotyledons, from one of the plants 

 with a sharp knife. Compare for a week the develop- 

 ment of the two plants and note the more rapid growth 

 of the plant from which the cotyledons have not been 

 removed. 



(2) Select four grains of corn and pare off from two 

 of them the starchy outer part {endos'perm) , with a sharp 

 knife, leaving only the germ. Plant these germs and the 

 two entire grains in a can of sandy soil and compare the 

 growth and development of the plants. 



Discussion: The young plant gets its first food from 

 the supply of material which is stored in the seed, tuber, 

 or other part which is planted. This stored material 

 should be sufficient in amount to supply the young plant 

 until it can send roots out into the soil to secure water, 

 which carries food materials in solution, and its leaves 



3 



