1. The intercellular matrix of the cells on the gills of Mytilus edulis is readily dispersed by hydroxyl ions.
2. All cations inhibit the action of hydroxyl ions, but the divalent metals are much more powerful than the monovalent metals. All divalent metallic ions except magnesium irreversibly coagulate the matrix at the hydroxyl ion concentration of seawater. This does not occur in the presence of magnesium ions.
3. There is a marked difference between the action of different non-electrolytes, since in the absence of salts the matrix remains stable for a much longer period in sugar, or glycerine, than in urea. Alcohol in certain concentrations has a marked stabilising action in the absence of salts.
4. With pure solutions of different monovalent sodium salts the anions can be arranged in a well-marked series in which the matrix is most readily dispersed in sodium iodide
I'< Br'. NO', < C1'< Ac'.
5. The relationship of the matrix to ions is similar to that between protein systems and ions, when attention is paid to both the electrostatic and lyophilic effect of the ions, and to the fact that the matrix is normally in equilibrium with a solution containing divalent metallic ions -- magnesium in particular. The analogy must, however, not be pushed too far.
6. The intercellular matrix of Mytilus cells can only possess a very slight electro-negative charge when in equilibrium with sea-water. If the constitution of the membrane is altered in such a way as to increase this charge, a type of matrix forms in which calcium is an essential constituent. Such a matrix appears to exist in echinoderms and in some other types.
- Copyright © 1926 The Company of Biologists Ltd.