304 PERMEABILITY IN PLANTS 



period without any bad after effects.^ This is also the case with 

 the other plants studied. 



It appears that in all the plants investigated there is a striking 

 agreement in essentials, though there is considerable diversity in de- 

 tails. It is therefore evident that the conclusions drawn from the 

 study of Laminaria are of general validity for all the plants investi- 

 gated. It is hoped that similar studies on animals may be presented 

 in the near future. 



SUMMARY. 



Quantitative studies on Laminaria (a brown alga), Ulva (a green 

 alga), Rhodymenia (a red alga), and Zoster a (a flowering plant) show 

 that the behavior of these plants, in respect to changes in permea- 

 bility, is essentially ahke in all cases. 



8 Osterhout, Bot. Gaz., 1915, lix, 242, 



