Experiments on Absorption of Salt-Marsh Plants. 12 i 
SOME EXPERIMENTS ON ABSORPTION BY THE 
AERIAL PARTS OF CERTAIN SALT-MARSH PLANTS. 
By Ann C. Halket, B.Sc. 
ROM time to time since 1904 accounts have appeared in this 
Journal of the work carried out under the direction of Prof. 
F. W. Oliver on the ecology of the salt-marsh at Erquy in Brittany. 
In the accounts of 1906 1 and 1907 2 mention was made of the work 
done by the “ physiological section ” in estimating the osmotic 
pressure of the cell-sap of the typical plants Salicornia spp. and 
Suceda maritima. Most of the work was done with Salicornia. 
Several species of Salicornia occur on the salt-marsh at Erquy 
and the individuals of some of the species, e.g., 5. ramosissima, 
vary greatly in colour and form. Determinations of the osmotic 
pressure of the cell-sap of the aerial parts of the various plants 
were made and the results obtained, although they varied very 
much among themselves, all agreed in being very high. Gaitong 3 
found that the root hairs of “ Salicornia herbacea ,” growing at the 
Bay of Fundy, were not plasmolysed by a 90% solution of the sea¬ 
water there, and Graves 4 working on Rnppia maritima found that 
its root hairs were not plasmolysed by a much stronger solution 
made by concentrating sea-water till it contained 110% sea-water. 
The values found for the osmotic pressure of the cell-sap of the 
succulent tissue of Salicornia from Erquy correspond to these, a 
result with which the values found for the root hairs by Hill 5 
agreed. The values found varied in different plants, and in 
different parts of the same plant between certain limits. These 
limits correspond to osmotic pressures equal to that of IT and P5 
gramme-molecular solutions, i.e., to solutions containing 6-4% and 
8-7% of sodium chloride. These values are much higher than 
1 F. W. Oliver. “The Bouche d’ Erquy in 1906.’’ New Phyt., 
Vol. V, p. 189, 1906. 
2 F. W. Oliver. “The Bouche d’ Erquy in 1907.” New Phyt., 
Vol. VI, p. 244, 1907. 
3 Ganong. “The Vegetation of the Bay of Fundy Salt and 
Dyke Marshes.” Bot. Gaz., XXXVI, p. 358, 1903. 
3 Graves. “ The Morphology of Ruppia maritima." Trans. Con¬ 
necticut Acad. Arts and Sci., Vol. XIV, 1908. 
* T. G. Hill. “ Observations on the osmotic properties of the 
root hairs of certain salt-marsh plants.” New Phyt., Vol. 
VII,1908. 
