Influence of Certain Carbohydrates on Green Plants 49 



The results as shown in table 18 indicate that as early as the fourth 

 day the sugars were exerting an accelerative influence on respiration, 

 and the relative differences between the sugar cultures and the checks 

 increased with the progress of time. For example, on the fourth day 

 the carbon dioxide evolution was 56 milligrams for saccharose culture 2 

 and only 41 milligrams for check culture 2; while during the last twenty- 

 two hours of the experiment it was 99 milligrams for saccharose culture 



Fig. 9. influence of glucose on root growth • 



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

 (Photographed through bottom of culture vessel) 



2 as compared with 34 milligrams for check culture 2. In the early 

 stages of growth the developing seeds had available the reserve food 

 of the cotyledons. Toward the end of the experiment, however, the 

 check plants were virtually starved, but the sugar-fed plants, constantly 

 absorbing food from the medium, developed in an almost normal condition. 

 The figures for carbon dioxide evolved during certain hours of daylight 

 are shown in the table in bold-faced type. In nearly every case it will 

 be noted that the carbon dioxide evolution in the daytime is greater in 

 cultures supplied with sugar than in those lacking sugar. This is due, 



