MUSCLE 



561 



the value of -^ second for the latent period of frog's 

 muscle. The tendency of later observations has been to 

 make the latent period shorter. Burdon Sanderson finds 



l 



FIG. 168. PENDULUM MYOGRAPH. 



At the left as seen from the side, at the right as seen from the front. A, bearings 

 on which the pendulum swings ; P, pendulum ; G, G', glass plates carried in the 

 frames T, T, ; a, pin which opens the trigger-key. The key, when closed, is in 

 contact with c, and so completes the circuit of the primary coil. 



that the change of form probably begins in muscle with 

 direct stimulation in T^ second after, and the electrical 

 change (p. 630) simultaneously with, the excitation. It is 



36 



