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



For trees: 

 r = +o. 127 =t= o. 152, K X io 6 = 9322 + 1464 A 



A = i . 1685 + 0.00001102 K X io 6 



For shrubs : 

 r = 0.079 =&quot;= o. 112, K X io 6 = 12059 IO 95 -^ 



A = i .2385 0.00000567 K X io 6 



For trees and shrubs: 

 r = +0.022 0.091, K X io 6 = 10591 + 273 A 



A = i . 1985 + 0.00000153 K X io 6 



For herbs : 

 r = +o. 150 0.052, K X io 6 = 11997 + 2 730-^ 



A = 0.7293 + 0.00000819 K X io 6 



The correlations between the freezing point lowering and 

 the electrical conductivity of the sap of ligneous plants are 

 of a very low order and statistically insignificant in comparison 

 with their probable errors. The value for shrubs is actually 

 negative in sign. That for trees and shrubs together is sensi 

 bly zero. The coefficient for herbaceous plants is also low, 

 but may indicate a slight relationship between the two con 

 stants, higher values of A being associated with higher values 

 of K and vice versa. 



These results show that, in the vegetation of the glacial 

 moraines of Long Island at least, there is practically no rela 

 tionship between the concentration of ionized electrolytes 

 and of total solutes (molecules and ions) in the leaf tissue 

 fluids. 



If there be little relationship between the magnitudes 

 of K and A one might expect the value of the ratio */ A to de 

 crease as A becomes larger and to increase as * increases in 

 magnitude. This is shown in Diagrams 3 and 4 to be the 

 case. 



The explanation of the lower conductivity of the tissue 

 fluids of ligneous plants presents a problem for future investi 

 gation. 



It may be suggested that the arborescent forms are ex 

 posed to greater insolation, and in consequence show greater 

 photosynthetic activity. A fragment of evidence in this 



