652 



QUANTITATIVE LAWS IN REGENTE RATION, II 



In Table I, a is the dry weight of roots and shoots formed by the 

 isolated leaves without stems ; b is the dry weight of the half stems 

 cut off from these leaves at the beginning of the experiment; a^ is the 

 dry weight of roots and of shoots formed by the sister leaves left in 

 connection with a piece of half stem, bi is the dry weight of the 

 latter half stems at the end of the experiment. According to our 

 theory the inhibitory effect of this piece of stem left in connection 

 with a leaf on the production of roots and shoots by the leaf should 

 be due to the fact that naturally the material (or the greater part of 



TABLE I. 



Dry Weight of Roots, Shoots, mid Half Stems. 



the material) used for root and shoot production in the leaf flows into 

 the stem and is utilized here for growth. We should therefore expect 

 to find that the dry weight of the half stem (bi) left in connection with 

 the leaf should increase as much as or even more than the difference in 

 the dry weight of the roots and shoots produced in the two sets of 

 sister leaves amounts to. If a is the mass of shoots and roots pro- 

 duced by the leaf isolated completely from the stem, ai the mass of 

 roots and shoots produced by the sister leaves left in connection with 

 the half stem, b the mass of the half stems at the beginning of the 



