ii8 PROTOPLASMIC ACTION AND NERVOUS ACTION 



Hober {op. cit., p. 371) cites certain observations of 

 Warburg made in 1911^ indicating that the erythrocytes 

 of the goose are influenced in their oxygen- consumption 

 by alkah-earth salts only after the plasma membrane 

 has been destroyed by freezing and thawing. Apparently 

 these salts cannot pass the intact plasma membrane. 

 On the other hand, alcohols and urethanes check oxida- 

 tions in the intact erythrocytes; these substances can 

 penetrate. It may be noted that these observations 

 are consistent with the view that the nuclear surface 

 is a chief factor in the oxidation-processes of these cells.^ 



The relative or complete impermeability of blood 

 corpuscles to the ions of the surrounding salt solution is 

 also indicated by the low electrical conductivity of 

 these cells. Stewart, Tangl,, Bugarszky, and others 

 have shown that the electrical conductivity of blood is 

 due almost entirely to the plasma. Low electrical 

 conductivity is in fact now known to be a highly constant 

 and characteristic peculiarity of cells during life, and 

 the evidence indicates that the high resistance is chiefly 

 if not entirely a property of the plasma membranes. 

 The conductivity of the cell as a whole appears to vary 

 directly with the permeability of the plasma membrane 

 to crystalloidal solutions. All conditions that increase 

 general permeability (action of cytolytic substances or 

 unbalanced salt solutions or of poisons, high tempera- 

 tures, or other lethal agents) also increase electrical 

 conductivity. According to Osterhout, the most exact 



^Warburg, Z. physiol. Chem., LXX (191 1), 413- 



2 In the nucleated erythrocytes of the frog, the indophenol test 

 shows active oxidation at the nuclear surface; cf. R. S. Lillie, Journal of 

 Biological Chemistry, XV (1913), 237. 



