CALLUSING 



91 



moisture can be controlled and the temperature will not 

 fluctuate too much. The floor of a cellar or storage house 

 would answer. 



For a small quantity, a box of suitable size would answer. 

 The bottom is covered with a layer of sand three or four 

 inches thick on which is placed a layer of grafts. These 



FIG. 41. Machine in Operation. 



are covered with a layer of sand, then another layer of grafts 

 and so on. The bundles of grafts may be stood on end if 

 desired, although the entire bundle should be covered with 

 sand. These must be examined from time to time during 

 the winter to see that they are kept moist and that the tem- 

 perature remains uniform. If the temperature runs too 

 high the buds will start and no callus form; if too low 



