12 



AINWALES DE l/INSTITl'ï l'ASTEUH 



stems reduced Ihe shoot production in the leaf moro llian the 

 shoilcr stems in expeiiment 1, namely 0,2116 gm. dry weiglit. 

 Hence we sliould expecl to find that the larger stem in exjxv 

 riment 11 had aiso gained more in mass than the shorter stem 

 in experiment 1, and Ihis was the case. The gain in mass ol" 

 the stems was 0,3382 gm. dry weight. In the third experiment 

 the 8 cm. long stems suppressed the shoot production in Ihe 

 leaf complotely, hut the controi leaves produced aconsidorably 

 smaller mass of shoots (0,16G2 gm. dry weight) than the con- 

 troi leaves in the two previous experiments, although the 

 experiments were made simultaneously and at identical tem- 

 pératures. It is possible that the illumination was not adéquate 

 or that the leaves were not in as good a condition as the others. 

 The stems in this experiment gained also less than the shorter 

 stems in experiment II, namely 0,3172 gm. 



Table VII. 



Thèse and similar experiments show, Jirst, that the inhi- 

 bition of shoot production in a leaf by a pièce of stem attached 

 to it is accompanied by an increase in the mass of the stem, 

 and, second, that this latter increase varies in the same sensé 

 as the inhibiting effect of the stem upon shoot production in 

 the leaf. In view of this fact and in view of the facts given in 

 the first part of this paper it seems, therefore, highly probable 

 that the inhibiting action of the stem upon the shoot production 

 in the leaf is due to the absorption of material from the leaf by 

 the stem. 



