SAMUEL ERNEST POND 



821 



TABLE VII. 



Contraction-Wave in Ventricle of Turtle. 



Record. 



Solution. 



Conductivity 

 (Ringer = 1.00). 



Velocity 

 per second. 



- =ife. 



Experiment 154; Wave Distance =1.6 cm.; 20°C. 



Experiment 155; Wave Distance = 3.0 cm.; 20°C. 



Turtle. — Strips cut from the ventricle of the river terrapin were 

 used in 1917 and 1921 with two different recording devices. The 

 earlier observations were recorded by means of levers writing on 

 smoked paper; in the later experiments the optical recording device 



