STUDIES IN PLANT RESPIRATION AND PHOTOSYNTHESIS. 



43 



2. GlycocolL 



That amino-acids accelerate the rate of carbohydrate consumption 

 in the leaves becomes evident from the following experiment: A 

 number of healthy leaves of about the same age were cut from the 

 plants in the manner already described and placed in battery jars. 

 In one set the petioles were put in 100 c. c. nitrogen-free nutrient 



Table 18. 



solution plus 100 c. c. of water; in the other set the solution consisted 

 of 100 c. c. of the same nutrient solution plus a solution of 0.5 gram 

 glycocoU in 100 c. c. of water. These solutions were steriHzed as 

 usual and the experiments carried out in duplicate. After remaining 

 in the dark for 72 hours at 20°, all the leaves were removed from the 

 jars and analyzed. The results of the analysis are given in table 18. 



Table 19. — Rate of €0% emission of 8 leaves of Helianthus annuris at 24°. 

 Petioles in nutrient solution containing 0.11 per cent of glycocoU. 



From the results given in table 18 it appears that the leaves 

 placed in nutrient solution gained only in amino-acid content and 

 that the leaves placed in a glycocoU solution showed an even greater 

 gain in amino-acids. It is also evident that the leaves fed glycocoU 

 consumed more carbohydrates than did the ones which had been 

 placed in nutrient solution only. 



