1903.] Nervous Impulse in Tall and Short Individuals. 



FIG. 1. 



415 



Fia. 1. Frogs VII and VIIT. Simultaneous record of twitches. K" = excitation 

 from " near " pair of electrodes. F, from "far." 



Experiments. 



From these measurements it is clear that the rapidity of the nervous 

 impulse per unit length is the same in all the frogs examined. As 

 the total length of the sciatic varied from 50 30 mm., the time 

 taken to travel from the central to the peripheral end was, therefore, 

 proportionately longer in the larger frogs. 



Series II. ON MAX. 



The method adopted was that elaborated by Waller.* A sensitive 

 41 Sandstrom " air tambour was connected by flexible tubing to a 

 hollow rubber cylinder held in the hand, so that the contraction of the 

 flexor muscles of the fingers would compress the cylinder. The excita- 

 tion was by break induction shock to the median nerve, the anodef 

 being applied (1) above the clavicle; (2) at the bend of the elbow 

 internal to the biceps tendon, the kathode being applied on any 



* Waller, A. D., ' Exercises in Practical Physiology,' Part III, p. 63. 

 t This position of the electrodes was found to give more concordant results than 

 the visual practice of placing the kathode over the nerve. 



2 G 2 



