70 Physico-Chemical Properties of Vegetdble Saps [March, 



Notwithstanding the considerable period of time over which these 

 collections were made, and the possibility that some of the more 

 extreme values may be due to some undetected error of determina- 

 tion, the ränge of osmotic pressure is actually rather narrow; 

 though, when considered in comparison with the mean pressure, it 

 is relatively rather wide. Expressing the results in the more log- 

 ical terms of Standard deviation, we find : 



Prolification 

 0.363 + 0.046 

 0.180 + 0.025 

 0.488 + 0.055 



The collections from Series E, which were made over a wide ränge 

 of time and conditions, are distinctly more variable. This con- 

 clusion, based on the Standard deviation, is substantiated by the 

 determination of the coefficients of Variation. 



With regard to the relative conditions in the wall and the in- 

 cluded mass, the results of this measurement of the concentration 

 of non-electrolytes, and dissociated and non-dissociated electrolytes, 

 are in close agreement with those for electrolytes alone, as meas- 

 ured in terms of conductivity. There is a lower osmotic pressure 

 in the sap of the included mass than in the ovary wall. The great 

 majority of these differences are of sufficient magnitude to be cer- 

 tainly significant. The data here are very consistent. Only three 

 exceptions are f ound : in two the prolification has a greater osmotic 

 pressure than has the sap from the ovary wall; in one the results 

 are identical.® 



Turning to the summary giving the mean osmotic pressure for 

 wall and abnormal tissue, and their differences, we note that the 

 osmotic pressure of the sap of the included mass is from one half 

 to one atmosphere lower than that of the wall of the fruit in which 

 it is produced. Expressing the difference in percentages, as in the 

 case of conductivity above and using as a base the mean for the 

 ovary wall, we find that the osmotic pressure is 12. i, 7.0 and 6.5 

 percent lower in the mass. These relative values are distinctly 



9 These three cases occur in one of the two small series. No explanation 

 can be given. 



