Mason — Inhibition of Invertase in the Sap of Galanfhus nivalis. 93 



In Table X are shown the changes in the depression of the freezing-point 

 observed on incubating some sucrose and hexose solutions to which were 

 added samples of sap pressed from leaves gathered at 4 p.m. and midnight 

 respectively of April 7th. The tissues were rendered permeable by the 

 freezing treatment ; the sap was not filtered, but was stored in ice till the 

 following morning. To 25 c.c. of the sap pressed from each sample were 

 added 75 c.c. of a 6 per cent, sucrose and hexose (invert sugar) solution 

 respectively. The solutions were kept saturated with toluene. 



The depressions on the left and right of figures 4 and 5 refer to the hexose 

 and sucrose samples respectively. 



aeos 



Jo- 397 



O 10 20 30 40 50 60 70 90 90 



TIME IN HOURS 



Fig. 4. 



