756 



SCIENCE 



[N. S. Vol. XLIII. No. 1117 



conceivable that, when naked protoplasm comes 

 in contact with an environing medium, like 

 sea-water, capable of supporting life, the 

 dispersed particles of fatty or lipoid material 

 which find themselves immediately on the sur- 

 face in contact with the sea-water are im- 

 mediately influenced by the Ca in the sea- 

 water. The system which consists of fatty or 

 lipoid material, dispersed by means of a soap 

 film in water, might be converted more or less 

 perfectly into the reverse type of system, in 

 which water is dispersed by means of a soap 

 fihn in an external fatty or lipoid phase. The 

 permeability of such a system to water, the 

 extent to which water channels would be 

 formed from point to point through such a 

 iilm or membrane, might well depend on the 

 proportions of those electrolytes like CaCL, 

 on the one hand, which tend to render the sys- 

 tem less permeable, and those like ITaCl, on 

 the other, which exert the reverse effect. Talv- 

 ing as an example the conversion of a disper- 

 sion of particles of wax in water into a honey- 

 comb-like structure in which the water phase 

 is surrounded by the continuous wax walls of 

 the cells, it can readily be appreciated that any 

 agent capable of corroding or perforating the 

 walls of the honeycomb structure would pro- 

 mote the continuity of the previously dispersed 

 water phase, and ultimately open up water 

 channels of communication throughout the 

 whole system. Agents capable of exerting the 

 reverse effect, tending to protect the wax walls, 

 would obviously antagonize the agents corrod- 

 ing or breaking down the walls, with the re- 

 sult that the permeability of such a system 

 would depend ultimately upon the proportions 

 in which the antagonistic agents in question 

 are present in the system. The writer believes 

 that a somewhat similar explanation might be 

 found for the formation of the protoplasmic 

 film, and that the antagonism between electro- 

 lytes possessing a more readily adsorbed cat- 

 ion, which tend to promote the formation of 

 a less permeable system, and those possessing 

 a more readily adsorbed anion, which tend to 

 exert the reverse effect, may be accounted for 

 on the lines indicated. 



Proteins present in protoplasm being trans- 



formed under the influence of Ca into a non- 

 reversible system analogous to a blood clot 

 might well form a sort of framework and con- 

 fer a certain rigidity, elasticity, and continu- 

 ity to the membrane structure. Fatty or lipoid 

 materials which produce readily reversible 

 emulsion systems in conjunction with water, 

 when supported by a protein framework, might 

 yield a system sufficiently sensitive to exhibit 

 variations in permeability to water under the 

 influence of varying proportions of such an- 

 tagonistic electrolytes as NaCl and CaCL,. 



C0„, and other products of metabolism, 

 exert a profound effect upon the equilibrium 

 and relative surface tension relations of inter- 

 facial soap films, and it is hoped in a subse- 

 quent publication to demonstrate that, under 

 the influence of variations in the proportions 

 of products of metabolism and electrolytes at 

 given points in the system, rhythmical varia- 

 tions in permeability may be produced in the 

 protoplasmic film permitting of the intake of 

 food stuffs and output of waste products, and 

 functioning in a manner somewhat analogous 

 to the valve system of an engine or machine. 

 If we consider the analogy of such a valve sys- 

 tem, since the efficiency of a mechanical system 

 may be entirely destroyed by too greatly in- 

 creasing or too greatly diminishing the size 

 and speed of action of the valves, it is not 

 difficult to understand how substances like 

 CaCh, by diminishing the permeability, and 

 substances like NaCl, by increasing the per- 

 meability of the protoplasmic membrane be- 

 yond those comparatively narrow limits within 

 which vital functions may be performed, 

 would ultimately cause a sufficient disturbance 

 of colloidal equilibrium to bring about what 

 we designate as the death of the cell. The 

 variations in electrical potential exhibited be- 

 tween the inside and outside of the cell, and 

 the electrical effects exerted by given salts 

 correspond with this theory. These experi- 

 ments with antagonistic electrolytes afford 

 substantial support to the theory, first ad- 

 vanced by A. B. Macallmn, that the similarity 

 in the proportions of certain electrolytes in 

 sea-water, the blood of mammals, etc., is at- 

 tributable to the fact that living protoplasm 



