50 



REGENERATION 



the regeneration of shoots in the stem proceeds is not yet per- 

 fectly developed. It is well, therefore, not to use in these experi- 

 ments that part of the stem which is too near the apex. It 

 may also be well not to use pieces of stem too near the roots. 

 After 3 to 5 weeks the dry weight of the shoots and of the stem 



Fig. 41. — Similar experiment as Fig. 40, except that the small pieces have 2 

 nodes each. Shoots and roots are formed in proportion to mass of stem. Dura- 

 tion of experiment, Nov. 16 to Dec. 19, 1921. 



used in these experiments was determined. Since some of the 

 small pieces of stem often fall a victim to fungi only one of the 

 two small basal pieces was used as a control. 



K 



