Influence of Certain Carbohydrates on Green Plants 69 



SUMMARY 



1. Corn {Zea mays L.) grown in nutrient solutions containing certain 

 sugars is able to absorb these sugars by means of their roots, and the sugars 

 are assimilated, effecting increased growth of the plant. 



2. The sugars, in the order of their beneficial effect on the plant when 

 grown in the hght, are, fii'st glucose and fructose, second saccharose, and 

 third maltose. In the dark glucose again leads, while the other sugars 

 are much alike. 



3. The embryo of corn wiU develop in the absence of all endosperm 

 material, and the presence of maltose increases growth. The production 

 of pigment is progressively increased with the increase in concentration 

 of glucose. 



4. Canada field pea (Pisum sativum L.) responds in growth markedly 

 to the presence of sugar ; the sugars in the order of their beneficial influence 

 being saccharose, glucose, maltose, and lactose. 



5. Timothy utilizes glucose and saccharose, but not lactose when 

 grown in the light. When grown in the dark lactose, as weU as the other 

 sugars, appear to be utilized. 



6. Experiments with radish (Raphanus sativus L.) confirm the earlier 

 investigations, glucose, saccharose, maltose, and lactose being utilized. 



7. Vetch {Vicia villosa Roth) grown in the dark utilizes the various 

 disaccharides, the order, as regards favorableness, being saccharose, 

 maltose, and lactose. On vetch grown in the light the favorable influence 

 of the different sugars is in the following order: saccKarose, glucose, 

 maltose, and lactose. 



8. Data are herein presented showing the influence of sugar on the 

 growth and respiration of vetch. The saccharose and glucose cultures 

 are much alike in their effect during the period of the experiment; the 

 maltose culture shows a lesser evolution of carbon dioxide. In the presence 

 of saccharose the seedlings grown in the absence of carbon dioxide main- 

 tained practically the original weight of the seed, but in these experiments 

 carbon dioxide equivalent to 0.822 gram of glucose in one case and to 

 0.8195 gram of glucose in another case was evolved. Somewhat similar 

 results were obtained with glucose and with maltose. 



9. The influence of sugar on respiration was manifest as early as the 

 fifth day of the experiment. 



