790 SALT ANTAGONISM IN STARFISH EGGS 



have a similar general significance. The coherence of the ciliated 

 cells in the gill epithelium of mollusca (Mitylus) is similarly lost 

 in pure isotonic solutions of many Na salts, in which also the cells 

 absorb large quantities of water ;i2 these effects are prevented by the 

 addition of Ca to the solution. The action of pure NaCl solutions 

 in increasing the permeability of plant tissues to ions/^ and of struc- 

 tures like the membrane of the Fundulus egg^^ to salts and water, 

 is closely related to the above; similarly with the breakdown of pro- 

 toplasmic structures like cilia and plasma membranes in this solu- 

 tion ;^^ here the structural continuity is lost and with it the dependent 

 properties of coherence and semipermeability. In all of these cases 

 an essential part of the protective or antitoxic action of the calcium 

 consists in preventing physical disintegrations of this kind; such 

 disintegrations are apparently the direct result of replacing solid 

 water-insoluble material and structure by water-soluble. 



The difference between the water-combining powers of Na and 

 Ca proteinates has been pointed out recently by Loeb in a series 

 of papers on the influence of inorganic salts on the physical proper- 

 ties of proteins;'^ here also characteristic salt antagonisms affecting 

 physical properties such as viscosity, swelling, osmotic pressure, pre- 

 cipitability by alcohol, are observed when tHe Na and Ca salts are 

 present in certain proportions.^^ It seems probable that certain 

 types of biological salt-antagonisms are to be explained by reference 

 to general facts of this kind; the case of the Fundulus egg, where the 

 toxic action of the pure NaCl solution is associated with a destruc- 

 tion of the water-proof character of the membrane or chorion en- 

 closing the egg," appears to exemplify this condition. In the case 

 of antagonisms in living protoplasm, however, not only the proteins 

 but other compounds, and especially the lipoids, appear to be es- 

 sentially concerned. The salt antagonisms studied by Clowes,^ which 



12 Lillie, R. S., Am. J. Physiol, 1906-07, xvu, 89. 



13 Osterhout, W. J. V., Science, 1912, xxxv, 112; xxxvi, 350. 

 ^^Loeb, J., Science, 1912, xxxvi, 637; Biochem. Z., 1912, xlvii, 127. 



15 Lillie, R. S., Am. J. Physiol, 1903-04, x, 419; 1909, xxiv, 23; 1912-13, 

 xxxi, 259. 



i«Loeb, J., /. Biol Chan., 1917, xxxi, 343; 1918, xxxiii, 531; 1918, xxxiv, 77. 

 1^ Loeb, J., J. Biol Chem., 1917, xxxi, 3; 1918, xxx-iv, 395; 489; and xxxv, 497. 



