176 



BOTANICAL GAZETTE 



[FEBRUARY 



was removed by Na 2 S0 4 . In the filtrate reducing sugars were * 

 determined before and after subjecting it to the standard method 

 for the hydrolysis of sucrose by HC1. The Bertrand titration 

 method was used for determining the amounts of copper reduced. 

 The results are expressed as glucose and sucrose respectively, 

 although it is recognized that other sugars are undoubtedly included. 

 Total nitrogen was determined in both the soluble and insoluble 



TABLE V 

 Catalase activity in shoots of Vicia Faba exposed to 



GRAVITY (EXPRESSED AS CUBIC CENTIMETERS OF OXY- 

 GEN LIBERATED BY 0.20 GM. OF MATERIAL) 



Time of exposure 



30 minutes 

 30 minutes 

 30 minutes 

 30 minutes 

 30 minutes 

 $0 minutes 



1 hour. . . 



1 hour. . . 



1 hour. . . , 



1 hour. . . 



1 hour. . . , 



1 hour. . . , 



2 hours . . . 

 2 hours . . . 

 2 hours. . . 

 2 hours. . . 

 2 hours. . . 

 2 hours . . . 

 4 hours. . . 

 4 hours . . . 

 4 hours . . . 

 4 hours. . . 

 4 hours . . . 

 4 hours. . . 



Upper flank 





7 



8 

 8 

 8 



9 



7 



9 



9 

 12 



15 



.20 



•45 

 .40 



.00 



. 10 



.85 

 .40 



.20 



10.20 

 8.00 

 8.80 



9 -85 

 8.80 



10.10 



11.30 



7.10 



8.60 



9 25 



7.40 



5 i5 

 8.80 



7.10 

 8.65 



Lower flank 



7.80 

 8.00 



7.50 

 6.30 



IO.70 



6.70 



8.65 

 8.20 



II.40 



9.00 



7SO 

 8.70 



IO.05 

 9.00 



9 95 

 11.00 



7.40 

 7.60 



9-3o 

 7.10 



6.60 



8.50 

 6.60 



7.60 



Difference 

 +O.65 



— o. 20 



-°-95 



— 2.10 



+ 1.70 

 —0.40 



— 1.20 



— 1.20 

 -0.80 



— 1.20 

 —0.50 

 —o. 10 

 +0.20 

 +0.20 

 -0.15 



— o 



+0 



— I 



+0 



— o 



+1 



— o 

 — o 



— I 



•30 



•30 



.00 



•05 

 ■30 



■45 



30 

 50 



05 



portions by the K jeldahl method. The results are given in table VI. 



The differences in direct reducing 



sugars, "glucose/ 7 are com- 

 paratively slight. Those in reducing sugars formed on hydrolysis. 



" sucrose ," 



are considerably greater, especially when figured as 

 percentages of the total. It is to be remembered, however, that the 

 total amount of sucrose is relatively small, and that the errors in 

 both determinations may accumulate in that of sucrose. It seems 



