100 



PLANT PROPAGATION 



less. Many devices, some of them very simple, have 

 been adopted for regulating both heat and moisture. 



143. Moisture regulation is accomplished usually by 

 propagating frames and boxes of various forms, the com- 

 monest being that of a hotbed but smaller. In all the 

 principle is that of confining the air. In a small way a 

 flower pot or a flat may be inverted over the cuttings, 

 (Fig. 32) or a pane of glass (Fig. 32) or a bell jar placed 

 above them. By tilting these more or less the humidity 



\ "*^Nr -.AA**. ^ 



-,\ k\ 



FIG. 90 METHOD OF POTTING 



1. Right hand partially filling s 

 2. Ready to plant. 3. Filling pot. 



>il into pot, left hand seizing rooted cutting. 

 4. Finishing. 



and the circulation of air may be easily regulated. What- 

 ever is used should admit light in varying degree. 



144. Callus, the new formation of cells upon an injured 

 surface ; for instance, at the lower end of a stem cutting, 

 or the cut surface of a layer or of a root graft. 



145. Stock plants are grown in greenhouses and 

 nurseries merely to supply cuttings, cions, layers, or buds 

 for propagation. 



146. "Blind eyes" are shoots which do not produce 

 flowers. They are common on roses and some other 



