Influence of Certain Carbohydrates on Green Plants 43 



Here again the results are not so consistent as might be expected. The 

 only conclusion to be drawn is that sugar is absorbed and increases the 

 growth of the plants. Saccharose again appears to be more beneficial 

 than glucose or maltose. Further evidence is obtained relative to the 

 secretion of invertase from the roots. 



influence of glucose on root growth 

 In every culture in which a sugar was used a very marked effect on 

 root growth was noted. In one experiment vetch was grown for ninety 



Fig. 6. influence- of glucose on growth of roots of vetch 

 Left, check (no sugar); right, glucose culture 

 (Photographed through bottom of large glass cylinder) 



days, on the one hand in 0.05 molecular concentration of glucose and 

 on the other hand in the absence of glucose. The influence of the glucose 

 on root growth is graphically illustrated in figure 6. 



influence of sugar on respiration and growth 

 Palladine (1901) noted the influence of various sugars on the respiration 

 of etiolated leaves of Vicia Faba. The leaves were left for a time in various 

 sugar solutions and their respiration was then determined. The sub- 

 stances used, in the order of their accelerating effect on respiration, were 

 fructose, glucose, saccharose, maltose, raffinose, glycerin, and mannite. 



