266 



Bayliss and Starling, 



the otliei piece of ebonite d) was fitted a brass tube carrying- a tam- 

 bour at its extremity; tbis tambour was provided with a button ar- 

 ranged to be opposite the end of the basal electrode. It will be seen 

 that the latter electrode is an adaptation of Frédéricq's „pince cardio- 

 graphique." By means of the tambour the beats of the heart were 

 registered at the same time as the electrical variations. The glass 

 tubes were introduced through small incisions in the left auricular 

 appendage, and were tied in, scarcely any blood being lost in the pro- 



Fig. 6. 



cess. They were then carefully pushed into the ventricular cavity 

 and when in position the ebonite blocks were put on to them, the 

 spring and the button of the tambour adjusted to press slightly on the 

 ventricle and keep the electrode in contact with it. 



3. The only other path possible for the excitation wave is 

 through nerves, and we think that our experiments suggest the possi- 

 bility that, under normal conditions, the wave of excitation excited by 

 an auricular contraction travels along a nerve network, from base to 

 apex of the ventricle, and that the muscular fibres are excited from 

 these nerves. Such a nerve network has been shown to exist in ven- 

 tricular muscle by Openchowski ^) and others. 



•) Archiv f. Mikros. Anat. Band XXII. 



