90 



BOTANICAL GAZETTE 



[august 



three times as great, in Raphaiius sativus it is over twice as 

 great, and in Allium cepa still in excess, although the difference 

 is not great. The results were what might anturally be expected 

 when we consider the aquatic habitat of Nuphar. 



6, CUCUMIS SATIVUS. 



For the garden cucumber measurements were made for juice 

 extracted from leaves, stem, and fruit. The roots being small 

 it w^as not possible to obtain the amount of juice necessary to 

 make the measurements. The results are as follows : 





Sp. cond. of 

 juice 



Crude ash from 



CCC 



sp. cond. ash 

 sol. 





0.0127 



O-O62I 



0.01096 



1 



4 



Stem 



0.0149 



0.0609 



0.01497 



F 



Fruit 



1 



0.00632 



0,0182 



0.00383 





This is the only species in w^hich the juice obtained from the 

 fruit was measured, and the examination of fruits of other species 

 is highly desirable. In this instance it will be seen that the 

 specific conductivity found for the fruit is only about half that 

 found for leaves. Here is also another instance in which the 

 specific conductivity of the juice from the stem is greater than 

 that found for the leaves and is not in accord with the amount 

 of crude ash found. 



The specific conductivity^ of the solutions made from the ash 

 of leaves and stem indicates that little besides the ash constituents 

 were responsible for the conductivity of the juice. For the fruit 

 ash, the specific conductivity is but little over half that of the 

 original juice, w^hich indicates that other substances than the ash 

 constituents were concerned. Litmus tests and titrations indi- 

 cated that the conductivity was produced partly by the acid 

 content of the juice. 



