FREDERICK CRESCITELLI 



187 



Fig. 7. A and B action potentials at low and normal temperatures. Records 1-21 : 

 blocking action of KCl at a concentration of 15.2 niM. 



Records 1-11: temperature 1.1°C. Record 1 is control. Electrograms taken at 1' 

 (2), 3' (3), 4' (4), 5' (5), 7' (6), and 8' (7) after test solution. Ringer wash occurred 

 at 9' and recovery records are shown for 11' (8), 12' (9), 13' (10) and 18' (11). 



Records 12-21: temperature 22.7°C. Record 12 is the control. Electrograms 13-19 

 were obtained at 1', 5', 10', 15', 17', 20' and 25' after adding test solution. Ringer 

 wash occurred at 26' and recovery records are shown for 27' (20) and 28' (21). 



Records 22-44: responses to sodium. TMA was employed as osmotic substitute. 

 Records 22-34 : temperature 3.1°C. Record 22 is the control. Electrograms 23-31 were 

 made at 3', 7', 9', 10', 11', 12', 13', 14', and 15' after adding solution lacking sodium 

 ions. At 33' Ringer wash occurred and recovery is shown for 33'10" (32), 34' (33) and 

 36' (34). Between 15' and 33' the responses to a solution with 11 niM NaCl were 

 examined but these are not included in the figure. 



Records 35-44: temperature 21.7°C. Record 35 is the control. Records 36^3 were 

 taken at 4', 9' , 13', 15', 19', 22', 24' and 25' after adding a solution lacking sodium ions. 

 Ringer wash occurred at 35' and reco\ery for 36' (44) is .-^hown. Between 25' and 35' 

 the responses to a solution with 11 mM NaCl were examined but these are not included. 



