OSMOTIC PRESSURE IN PLANTS 



'95 



level. The reverse, however, is sometimes found, as in 

 Experiments 6 and 7, where the pressure in the lower is 

 much greater than in the higher leaves. 



Table 31. 

 Osmotic Pressure and Height above Ground Coiutared. 



The possibility that these discrepancies might be due 

 to resistance in the conducting tracts apart from that 

 offered by the hydrostatic head had to be examined, and 

 Experiments 80, 81, 82, 83 on Wistaria sinensis and 21, 

 22, 23, 24 on JJlm.us campestris (recorded in Tables 32 

 and 33 respectively) were carried out. 



Table 32. 

 Wistaria sinensis : sap from untreated leaves. 



Under M are given the mean molecular weights of the solutes calculated 



from the dry weight and freezing-point of the solutions. 



o 2 



