THE PERMEABILITY OF CELLS 



531 



fairly constant. In all the experiments on alkalies, N means 

 normal, equivalent to corresponding normal solutions of HCL. 



The rate of entrance when the cells have been killed in various 

 ways is shown in tables 2 and 3. 



TABLE 2 



Times for different concentrations of NaOH to deodorize the neutral red tannin compound within Spirogyra 

 threads. In column A are figures for the living plant; in B for threads killed by boiling water and stained 

 in neutral red; in C for threads killed by ~^ HCL (3 mins.) and washed free of acid; in D killed by 

 CHClt water (1 min.), and in E the threads were killed by a saturated solution of HgCh (3 mins.) 

 and washed in water. The NaOH was dissolved in tap water and the solutions tested in corked bottles. 



TABLE 3 



Penetration of different concentrations of NaOH into Elodea leaves. The NaOH was dissolved in tap water. 



It is found that all alkalies may enter with practically no 

 resistance providing the cell surface has been destroyed in some 

 way; it is immaterial how. Thus in /^ NaOH Spirogyra threads 

 retain their red color about 3,5 hours, but if treated with CHCIa 



