ALIMENTARY CANAL IN THE BEE 



537 



four and forty-eight hours standing at 36-40° C. the rotation 

 of the polarization plane was determined in the mixtures. 

 The results obtained are represented in Table YITI. 



Curve 3. 



25 cu cm of 

 ertract from the mid- 

 gut of the tees 



Curve demonstrating the depressive effect of glycerine upon the activity 

 of invertase, based on the data of the series of experiments nos, 37 and 38 

 (see Table VII). 



It is seen from Table VIII that invertase is extracted both 

 by water and a mixture of water and glycerine, by glycerine 

 alone, as well as by the physiological solution of common salt. 



Evidently the most active extracts are produced by water, 

 less by glycerine. Water, however, can be used effectively 



