LABORATORY PRACTICE 



III. Adventitious roots have already been examined in 

 the seedlings of Indian Corn. Examine the base of an 

 adult Corn Stalk and notice that : ^- 



1. The primary roots have disappeared long ago. 



2. Each of the lower nodes of the "stalk" or stem bears 



a circle of secondary roots, extending out obliquely 

 downwards, and as the nodes and roots die away 

 below, new secondary roots are formed at the nodes 

 above. 



3. Make a sketch showing these points. 



4. Why does the farmer " hill up " the Corn? 



IV. Root Hairs. Examine the roots of the Pea, Bean, 

 and Corn, grown in loose, damp sawdust (or in a moist 

 chamber), with a lens. Notice and sketch the root hairs. 

 Upon what portions of the roots do they occur? Of what 

 use are they to the plant? 



V. Summary and Questions. 



1. Of what two principal uses are the ordinary (or typical} 



roots to the plant? 



2. Why do we water the roots of the plants? 



3. Why are fertilizers placed about plants or in the soil in 



which seeds are sown or plants are planted? 



4. Why do the roots spread out below ground ? 



5. What are the differences between primary and secondary 



roots ? 



6. What are the differences between primary and adven- 



titious roots ? 



7. What is a tap root ? 



8. What are multiple primary roots? 



