100 



Chapter VI 



of saliva and the call for oxygen which is initiated by stimulation 

 of the chorda tympani. 



No. I (Fig. 57) gives the rate of oxygen consumption which follows a 

 short stimulus, 20 seconds, while No. II shows the consumption follow- 

 ing a stimulus of ten times the duration. Not only does the oxygen 

 consumption long outlast the stimulus in each case, but it does so 

 for a much longer time in the case of the longer stimulus. This is 



FIG. 58. a, b, c, oxygen used in active as compared with resting glands in individual 

 exps. d, line represents mean rate of salivary secretion in c.c. per minute in the 

 three Exps. S Sybase line for saliva. Black area oxygen used by the active as 

 compared with the resting gland. = oxygen base line. 



probably a fatigue effect to some extent, for in No. Ill, in which the 

 animal was in bad condition as a result of surgical shock, the call for 

 oxygen only manifests itself very slowly and has scarcely passed its 

 maximum at the right of the figure, that is to say almost six minutes 

 after the stimulus has ceased. 



Nor is it only as the result of chorda tympani stimulation that 

 we have this prolonged call. In the cat it follows upon stimulation 



