SECRETION PHYSIOL OG V. 307 



Experiment V. 



Large dog under morphine and chloroform. Right submax- 

 illary gland prepared. Chorda lingual and sympathetic cut. 

 Each nerve causes a good secretion. Readings as in previous 

 experiments. Canula in Wharton's duct. Secondary coil i 50. 

 Tetanic shocks. 



TIME. NERVE STIMULATED. SECRETION. 



h. m. s. h. m. 



5 49 30 Head cut off as rapidly as possible. 



Spinal cord and vertebral column 

 not severed. 

 5 50 30 - 5 55 Chorda (intennittent) 175 



5 55 " (coil 70) o 



5 57 Sympathetic (coil 7) 40, 20, 6, 2, 0. 



5 58 - 6 10 No stimulation. 



6 10 Sympathetic 4, 5, 2, 0, 0. 



Experiment VI. 



Dog. Conditions of experiment the same as in Experiment 

 V. Submaxillary. Both nerves active. 



NERVE. SALIVA SECRETED IN MM. 



Head completely severed from body. 

 Chorda intermittent 65 



Chorda. o 



Sympathetic. 14, 3, 2, 2, 0. 



The foregoing experiments, demonstrating that a sympathetic 

 secretion may be obtained ten minutes after all fluid and oxygen 

 have been cut off from the gland shows, I think, that Heidenhain 

 was wrong in ascribing the quick normal cessation of secretion 

 during sympathetic stimulation to the nerve's action on the 

 blood vessels. It is obvious that vascular constriction can have 

 nothing to do with such cessation, because the changes produced 

 in a normal gland by vascular constriction, namely, diminution 

 of water and oxygen, have existed in all three experiments at 

 least seven minutes before the nerve was stimulated, and con- 

 tinue during that stimulation without in any way affecting the 

 course of the secretion. 



Even a normal gland secreting a ver>^ viscous saliva furnishes 

 evidence against the truth of Heidenhain's explanation. In the 





TIME. 





m. 



S. h. 



m. 



4 



30 





31' 



40-4 



35 



4 



35-4 



38 



4 



38 





