206 PLANT SOCIOLOGY 



cryoscoiMC apparatus used for cell-sap determinations and expressed in 

 atmospheres. 



The following determinations made about salt pools near Mont- 

 pellier, France, in October, 1930, show that the concentration of the 

 water corresponds exactly with the zonation of the vegetation: 



Atmospheres 



1. Scirpeto-Phragmitetum, in a fresh-water canal emptying 



into the pond 0.4 



2. Phragmxtes isiacus sub-association with Scirpus maritimus . . 0.6 



3. Cladium mariscus community 1.7 



4. Scirpus maritimus, S. littoralis as.sooiation 8.8 



5. Scirpus maritimus mixed with SaUcornia radicans 22.4 



6. Salicornietum radicantis 27.4 



7. The salt water without vegetation 77 . 8 



