Stimulation of Root Growth in Cuttings 



125 



of the six experiments, especially at the higher concentrations, a partial 

 or total inhibition of shoot formation from, the upper nodes, while the 

 second or the third, or even the fourth, node below developed the more 

 vigorous shoots. Similar results after treatment with cane sugar are 

 shown in table 17 and in figure 8. In this case, however, there is no 

 increase in total top growth, as was found in most of the other experiments. 



Fig. 8. 



EFFF.CT OF SUGAR SOLUTIONS ON MATURE CUTTINGS OF LIGUSTRU.M 



In nearly every case shoots 



Upper row: Check twigs left for two days in water, then placed in sand, 

 formed only at the uppermost node 



Low'r row: Twigs left for two days in 0.4 mol. cane sugar, then placed in sand. In the majority of 

 twigs no .shoots were produced at the uppermost node. Root growth was slightly retarded 



FORCIBLE injection OF SUGAR SOLUTIONS 



Several preliminary experiments have been carried out in which sugar 

 solutions were forcibly injected into the intercellular spaces of the stems 

 of cuttings. The method is the same as that commonly used to increase 

 penetration of killing fluids. The cuttings were immersed in the solutions, 

 which were contained in heavy glass cylinders, and the pressure was then 

 reduced by means of a suction pump. As a result the gases rapidly 



