192 SOME RECENT EESE ARCHES IN PLANT PHYSIOLOGY 



Cotoneasterfrigida, Fagus silvatica, Ilex aquifolium, Populus 

 alba, and Salix babylonica. 



Under hexose and sucrose is given an approximate 

 estimate of the amount of these sugars present; when 

 5 drops of the sap decolorized 10 drops of Fehling's solu- 

 tion, xx xx is set in the hexose column, when equal 

 volumes were required x x , and when 20 drops of the 

 sap had to be used for 10 drops of the solution x is put 

 down. Under sucrose a similar notation is used, indicating 

 the volume of inverted sap required to decolorize the 

 copper solution. Allowance is made for hexose, if any 

 was found previous to inversion. In the same way a 

 barely perceptible reduction is indicated by + , and a 

 more marked trace by + + . It may be mentioned that 

 the values of these signs approximately correspond, 

 x x x x to 1 per cent., x x x to 0'75 per cent., x x to 

 0-50 per cent., and x to 0'25 per cent. ; + to O'Ol per cent., 

 and + + to 0-1 per cent. 



TABLE L. 



Acer pseudoplatanus : WOOD SAP FROM STEM AT S-METRE LEVEL, 



AND FROM ROOT. 



Where m is written in the sucrose column, the presence 

 of maltose was detected by phenyl hydrazine. Of course, 



