102 J ^ : PLANT BIOLOGY 



D. Corn seedling well advanced. 



1. What changes have taken place during the development 



of the seedling in the roots? in the plumule? 



2. How does the veining of the leaves in the corn plant 



differ from that in the leaves of the bean plant? 



3. Where do you find aerial or air roots on the corn seedling? 



(Roots growing above ground are aerial roots.) 



4. Pinch the grain between your fingers. What changes 



do you notice in the amount of food material ? How 

 can you account for these changes ? 



. 5. Make a sketch of the seedling and label corn grain, coty- 

 ledon, stem, leaves, aerial roots, soil roots. 



109. Suggestions for growing seedlings at home. (Optional.) 



A. Window box. Secure a wooden box at least six inches in 

 depth, and of a convenient size to place in front of a south window, 

 if you have such a window at home. Nearly fill the box with rich 

 earth which has been finely pulverized or sifted. If possible, mix 

 in thoroughly some well-rotted manure and a tablespoonful of pre- 

 pared fertilizer. Soak your seeds for twenty-four hours, and plant 

 them at a depth equal to four times the thickness of the seeds. 

 Cover the seeds with dirt, press it down firmly, and sprinkle with 

 water till the earth is thoroughly moistened to a depth of at least 

 four inches. See that your garden is kept as nearly as possible at a 

 temperature of 70 degrees. Add enough water day by day to keep 

 the ground moist. 



B. Tumbler garden. Secure several pieces of blotting paper 

 or other porous paper, and cut it about as wide as the tumbler is 

 high. Wet the paper and roll it into a hollow cylinder that fits 

 inside the tumbler. Between the blotting paper and the glass 



^ place the soaked seeds with their hilums in several different posi- 

 tions. Fill the interior of the tumbler with wet sawdust, cotton, or 

 crumpled paper. Cover the tumbler loosely and keep the contents 

 moist, and at a temperature of about 70 degrees. 



C. Glass-plate garden. 1 Secure two pieces of glass about 5X7 



1 The authors are indebted to Dr. Cyrus A. King, Head of Depart- 

 ment of Biology of Erasmus Hall High School, Brooklyn, N. Y., for 

 this method of germinating seeds. 



