Growth of Roots, Stems, and Leaves 



19 



Ex. 4. Place Zea mays seedlings where they are warm. When 

 the first blade is about 2 inches above ground, or as soon as the leat 

 which it is protecting has burst through, separate carefully with a fine 



Fig, 26.— Showing basal growth in Zea mays. 



needle, and strip from the sheath to expose the base of the leaf within. 



Mark off lines on the part exposed, carrying them across on to the sheath. 



When growth has taken place, 



so that the marks appear 



above the sheath, it will be 



seen that the place marked 



has been pushed up by the 



growth at the base of the 



leaf. 



Commelina ^ will be a 

 good plant for studying the 

 growth of a monocotyledon- 

 ousstem. Split the sheathing 

 base of the leaf and mark the 

 stem off. Mark other plants 

 — Flagellaria, or any of the 

 species oi Asparagus {Wachi- 

 een-heetje). Mark the stem 

 in Spring, when they are 

 growing rapidly. 



Direction of 

 Growth of Roots 



and Stems. — We have ^^^- 27.— Growth of the stem of Commelinn. 



^ Commelina is often cultivated ; it is found wild in the Eastern, Central, 

 and Kalahari Districts. 



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