JACQUES LOEB 457 



trol pieces produced approximately the same amount of shoots per 

 gram of stem, namely 30.4 mg. as compared with 28.0 for the large 

 pieces. 



Experiment II. November 2, 1921, to December 6, 1921. 



Dry weight of 



shoots r)er gram 



of stem. 



5 long pieces of stem with 6 nodes each. «>»• ««• 



Dry weight of stems 6 . 486 



" " 10 shoots 0.272 42.0 



" " roots 0.0458 



Control a. 4 short basal pieces with 1 node each. 



Dry weight of stems 1 . 058 



" " " 8 shoots 0.041 39.0 



" " " roots 0.0034 



Control b. 5 short apical pieces with 1 node each. 



Dry weight of stems . 544 



" " 10 shoots 0.018 33.0 



Again the short basal control pieces produce about as much shoot 

 material per gram (39 mg.), as the large pieces (42 mg.), while 

 the apical controls produce less, namely, 33 mg. We will omit the 

 apical controls in the further tabulation of experiments on account of 

 the irregularity of the results. 



Experiment III. November 16, 1921, to December 20, 1921. 



Dry weight of 



shoots per gram 



of stem. 



9 long pieces of stem with 6 nodes each. «'"• *"^- 



Dry weight of stems 18 . 658 



" " 26 shoots 0.944 50.3 



" " "roots 0.1428 



Control. 18 small basal pieces of 2 nodes each. 



Dry weight of stems 18 . 147 



" " 36 shoots 0.800 44.0 



" " " roots 0.136 



Experiment IV. October 22, 1921, to November 15, 1921, 

 4 long pieces of stem with 4 nodes each. 



Dry weight of stems 4.214 21.0 



" " 8 shoots 0.089 



Control. 4 short basal pieces of 2 nodes each. 



Dry weight of stems 2.492 19.0 



" " " 8 shoots 0.0475 



