142 Extraction of Sap from Plant Tissues 



review of the literature in the papers cited above, be glven to DIxon 

 and Atkins, it will be noted that our results somewhat extend theirs ; 

 in some minor regards, only, our results are not in füll accord with 

 theirs. 



EXPLANATION OF PLATE i 



In all the Diagrams in Plate i the heights of the bars indicate the amounts o£ 

 the lowering of the freezing-point, as shown on the scale to the left (i unit 

 = 0.1°). The cross-hatched bar to the left shows the concentration of the sap 

 from the " original f rozen sample." The lined column to the right shows that 

 of the " frozen residue." The concentrations of the successive fractions extracted 

 by pressure are shown (in order, left to right) by the unshaded bars. 



Diagram i. Sap from leaves from flowering plant of Syringa vulgaris. 



Diagram 2. Sap from leaves of a greenhouse culture of seedlings of several 

 dwarf varieties of Pisum sativum. 



Diagram 3. Sap from inner leaves of Cabbage; determinations made in 

 January. 



Diagram 4. Sap from leaves, probably not quite mature, of Symplocarpus 

 fcvtidus. 



