130 



W. M. Bayliss and J. R. Bradford, 



diminished in amount. The following experiment illustrates a ease in 

 which the variation was a pure second phase and the secretion very 

 scanty. 



Cat. — July 2. 1885. 







Distance 



Sign of outer 





Time 



Nerve 



of secondary 

 coil 



surface and galva- 

 nometer deflection 



Saliva 



1.10 



chorda 



60 mm 



+ 40 



scanty 



1.15 



it 



20 „ 



+ 540 



>> 



1.22 



5» 



20 „ 



+ 360 



very scanty 



1.26 



J> 



40 „ 



+ 130 



>■> ii 



1.34 



» 



40 „ 



+ 80 



no secretion 



In this case in order to get any secretion at all a strong stimulus 

 had to be used, and even then the amount of the secretion was very 

 small and the variation a pure second phase. With one exception, in 

 all the other experiments (about 15 in number) the chorda gave a fair 

 amount of viscid secretion, and the electrical phenomena consisted of 

 either a pure first phase or more usually a diphasic variation. When 

 a pure first phase was present, the amount of the secretion was always 

 markedly greater and less viscid ; than when a di-phasic variation was 

 observed. In the exceptional case stimulation of the chorda caused a 

 copious secretion, but the electrical variation indicated that the outer 

 surface of the gland became positive, although later a diphasic va- 

 riation was obtained. This was the only case of the kind obser- 

 ved by us. 



To recapitulate: In the cat excitation of the chorda produces 

 electrical variations similar to those occurring in the dog, but the 

 second phase (i. e. outer surface positive to hilus) is better marked, 

 so much so that occasionally it is the only one observed. It follows 

 from the above that the first phase (i. e. outer surface negative to 

 hilus) is usually not so large in the cat as in the dog, since its course 

 is interrupted by this second phase. Further it may be added that 

 the magnitude of the first phase appears to vary with the amount of 

 saliva secreted, and that the amount of the second phase appears to 

 vary with the viscidity of the saliva. 



