140 



J. A. Harris, R. A. Gartner and J. V. Lawrence 



While the materials are rather too meagre for exhaustive 

 statistical analysis they have been classified according to 

 the magnitude of A and the average value of K and of K/ A 

 for each class of A has been determined. The results are 

 presented in Tables IX and X. 1 



Diagram i , which shows by the position of the two means 



16 



Diagram i 



Average values of specific electrical conductivity, K, of leaf tissue fluids of 

 ligneous and herbaceous species classified according to freezing point de 

 pression, A. 



on the scale for A the conspicuous differentiation of ligneous 

 and herbaceous plants for this constant, also brings out 

 clearly the fact that for each grade of A the ligneous forms 

 have a lower electrical conductivity than the herbaceous 

 species. The mean values for K for the two growth forms lie 



1 The class interval of A has been selected to represent 5 percent of the 

 molecular lowering taken as A = 1.86. 



