JACQUES LOEB 



85 



In Experiment 4 the two masses of sister leaves were in the ratio of 

 almost 1:5, namely 2.7 : 11.9, and the masses of shoots produced 

 by the stem were also approximately in the ratio of 1 : 5, namely 

 0.53 : 2.7. 



Our experiments have shown without exception that the greater the mass 

 of a basal leaf the greater the mass of shoot regenerated by the apex of the 

 stem in equal times and under equal conditions; and wherever we were 

 certain that the leaves remained normal during the experiment it was also 

 possible to show that the mass of shoots produced by the apex of the stem 



TABLE I- 



Influence of Mass of Leaf at Base of a Piece of Stem upon Mass of Shoot Re- 

 generated at the Apex of the Piece of Stem. Apices of Leaves Dipping 

 in Water, Stems Suspended in Moist Air {See Fig. 2). 



varied approximately in direct proportion to the mass of the leaf attached 

 to the base of the piece of stem. 



Fig. 2 is a drawing of the appearance of a group of six pairs of 

 half stems having a leaf at the base. The duration of the experiment 

 was 21 days. The upper half stem with a whole leaf is always the 

 sister piece of the half stem with a reduced leaf immediately below it. 

 It is obvious that the stems with the reduced leaves have smaller 

 shoots than those with whole leaves. The apices of the leaves were 

 dipped in water, the stems were in moist air. Fig. 3 is a photographic 



