39° 



BOTANICAL GAZETTE 



[may 



coefficient falls off with the higher concentrations. It is believed 

 that this lowering of the rate is due to the increasing viscosity of 

 more concentrated sugar solutions. 





TABLE XIII 

 Ratios of rates 



5.15:10.30 



10.30:15.62 



2.170 



1-259 



I. 144 



2-133 



1.279 



I-305 



2.063 



1.284 



I.302 



1.734 



1-344 



I. 172 



1.919 



1. 441 



I. 209 



1.756 



1. 361 



1-234 



1.634 



1-354 



I. 214 



1.82s 



1.364 



I. 179 



1.947 



1.235 



I. 117 



1.792 



i-35i 



I.204 



1.753 



1-325 



x.233 



1. 712 



1 .302 



1 143 



2.000 



1235 



1.208 



u 



1. 168 



1.246 



a 



MM 



1.238 



1.249 



* 



X.2I< 



1 



20.22:48.0 



I. 292 



1.254 

 1.308 



Average, 1 . 888 



1.297 



1. 211 



1-285 



It was found that it was not possible to increase the concentra- 

 tion of the solutions on opposite sides of a membrane by an equal 

 amount on each side without changing the rate at which water 



membrane 



followin 



osmometer 



having a known osmotic 



movement 



Then the 



osmotic Dressure was increased on each side of the membrane 



amount 



XIII 



Thus, 



although the effective osmotic pressure exerting an influence upon 

 water movement was practically the same, the rate of water 



same 



much less. With 



same 



movement was not the 

 membrane the same osmotic pull does not give the same rate, but 

 the rate depends upon the distribution of the concentration on 

 opposite sides of the membrane. When the concentration of 

 the external solution was kept constant and the concentration 



of the internal Qnliitinn waQ \7*\r\(±A tfiA r^cnltc mvpn in table XIV 





