68 HORTICULTURE FOR SCHOOLS 



EXERCISE III. Callus formation. 



Materials. Stored or planted cuttings. 



Procedure. Examine cuttings from time to time. Draw a callus. 

 What factors are necessary for callus formation? Which of the cuttings 

 examined callus most readily? 



EXERCISE IV. Project: If the student is contemplating a project 

 involving propagation by cuttings, he should begin a systematic study 

 of the plants he intends to use so as to be ready with cuttings at the 

 opportune time. The following projects are suggested: Propagating 

 and growing blackberries, raspberries, currants, loganberries, goose- 

 berries, strawberries, or ornamental plants. 



