BIOELECTRIC PHENOMENA 321 



Changes of temperature influence the functional 

 processes and the bioelectric processes similarly. For 

 example, in a special study by Keith Lucas,' in which the 

 temperature-coefficient of the rate of development of 

 the bioelectric variation in the frog's sartorius was 

 compared with that of the propagation-velocity of the 

 excitation-wave, almost identical values were found for 

 the two processes. In a typical experiment, the time 

 required for the rise of the bioelectric variation from 

 zero to its maximum at 8° was .0041 of a second, and at 

 18°, .0024 of a second; the ratio of these two values, 

 I 1.64, was almost identical with that of the propagation- 

 velocities of the excitation-wave (contraction-wave) at 

 the two temperatures. In other words, change of 

 temperature influences the rate of protoplasmic transmis- 

 sion in the same manner as it influences the rate of 

 variation of potential. 



It seems clear that the bioelectric variations are 

 inseparably connected with chemical or metabolic 

 processes in the living cells, and that the characteristic 

 rate at which the tissue reacts and conducts excitation 

 is a direct function of the rate of both processes. This 

 rate is determined by the specific chemical and structural 

 constitution of the tissue as well as by external factors, 

 such as temperature and the state of the surrounding 

 medium. The evidence already reviewed indicates that 

 the essential changes underlying the bioelectric phe- 

 nomena occur at the cell boundary; hence, these phe- 

 nomena may be regarded as an index of chemical 

 decompositions or other reactions occurring in the 

 protoplasmic surface-films. Apparently these reactions 



^Journal of Physiology, XXXIX (1909), 207. 



