Groivth of Roots, Sterns, and Leaves 



19 



as the leaf which it is protecting has burst through, separate 

 carefully with a fine needle, and strip from the sheath to expose 



Fig. 26. — Showing basal growth in Zea mais. 



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, unlike the dico- 

 tyledon, growth has not 

 caused the marks to spread 

 apart, but the place marked 

 has been pushed up by 

 the growth at the base of 

 the leaf. 



Commelyna will be a 

 good plant for studying 

 the growth of a monoco- 

 tyledonous stem. It is 

 found wild, and in culti- 

 vated places. Split the 

 sheathing base of the leaf 

 and mark the stem. Mark 

 other plants — Flagellaria^ or any of the species of Asparagus 



Growth of the stem of Coinmelyfia. 



