REVIEW 



23 



Keview. — What are primary and sec- 

 ondary offices of roots and stems? What 

 are the offices of rhizomes ? How does 

 propagation by rhizomes proceed ? Why 

 does the colony spread ? Name some 

 plants which propagate by means of rhi- 

 zomes. What is a cutting? May cuttings 

 be made of rhizomes? How are rhizom- 

 atous weeds often spread ? How do roots 

 serve to propagate the plant? Name in- 

 stances. What are adventitious buds? 

 What is a layer? Define some of the 

 kinds of layers, — runner, creeper, stolon, 

 offset. Explain how cuttings may occur 

 without the aid of man. How may leaves 

 serve to propagate the plant? Explain 

 how plants propagate themselves by 

 means of detachable buds. What is a 

 graft? How may grafting take place 

 without the aid of man? 



Note. — If there is an accessible 

 "patch" of toad-flax, Canada thistle, 



May apple, or other perennial plant, the pupil should determine by 

 what means it enlarges from year to year. "Patches" are always 

 instructive when considered with reference to propagation and dis- 

 semination. 



31. A native graft. 



i;oluuy of ilay applt 



