ELECTRICAL CHANGES IN TISSUES 663 



Tn the skin of the frog, it has been shown that the electrical change can still 

 be obtained when the saline solution in the leading off electrodes is replaced by 

 water ; so that a clear proof is given that the electrical effect is not merely due 

 to the electrolytes of the leading off solution. In accordance with the membrane 

 theory, we find that both here and in the case of plant tissues the electromotive 

 force is modified by the concentration of the cations of the leading off solution. 



A brief account is given in the text of the electrical fish, and the interest of 

 the phenomena from the general point of view, as regards reflex co-ordination 

 and so on, is pointed out. 



The electrical phenomena in plants are readily explicable in terms of changes 

 of permeability of the cell membrane. 



LITERATURE 



Theory, 



Bernstein (1902 arid 1913). Beutner (1912). Bayliss (1911, 2). 



General Facts. 



Garten (1910). 



Voluntary Muscle. 



Keith Lucas (1908, 2, and 1909, 2). Piper (1912, 1). 



Electro-cardiogram. 



Mines (1913, 3). Einthoven (1913). Lewis (1913, 1). 



Methods. 



String Galvanometer. Einthoven (1901, 1903, and 1904). 



Capillary Electrometer. Burch (1890 and 1892). Keith Lucas (1909, 2). 



