130 



Mr. J. Gray. 

 Table III. 



Test tube. Test solution. Nature of resulting system. 



10 c.c. distilled water A uniform milk-white emulsion of oil drops 



in water. 



Discontinuous phase — Oil. 

 Continuous phase — Water. 



10 c.c. M,2NaCl Two phases separate out in equal volumes — 



(i) Water almost free of oil. 



(ii) Oil almost free of water. 



i 10 e.e. M/10 MgOL A uniform greasy emulsion of water drops 



in oil. 



Discontinuous phase — Water. 

 Continuous phase — On.. 



D 10 c.c M 10 CaCL, 



Same as C. 



E ' 10 c.c. sea- water Two phases separate — 



(i) A large volume of water drops in a con- 

 tinuous oil phase, 

 (ii) A small volume of oil drops in water. 



of the monovalent ions depends upon several factors : (a) their concentra- 

 tion, (6) the salts existing in the gel. In concentrations equivalent to those 

 used in the present series of experiments (viz., about M/2), the erosive 

 power of LiCl is much less than that of Na or K. A study of Schryver's 

 results shows that the analogy between them and the experiments here 

 described is strong. It remains, however, to be proved that such a system 

 as a cholate gel possesses the same semipermeable properties as a living 

 membrane. 



Summary. 



(i) The ciliated cells of Mytilus edulis are insensitive to the following 

 anions : 



CI', MV, Br', I', Acet', S0 4 ", 



as long as the normal equilibrium of the cations USTa', K', Ca" and Mg" is 

 maintained in the surrounding medium. 



(ii) In solutions containing tartrates and citrates, the bivalent metals 

 Mg" and Ca" are probably not present in the ionic state, and the cells 

 behave as though these metals were absent. 



(hi) There is no justification for the statement that the order in which 

 anions affect ciliary motion is the reverse of the order in which they affect 

 muscular movement. 



(iv) Pure solutions of sodium salts destroy the normal semipermeable 

 nature of the cell-membrane, and the cell colloids behave as an elastic gel 

 in direct contact with the external medium. 



