308 MATHEWS. 



resting submaxillary of the dog the sympathetic secretion may 

 have a latent period of many seconds and persist for minutes. 

 An instance of such a kind is the following : 



Experiment III. 



Large moi*phinized dog, receiving chloroform. Both chorda 

 lingual and sympathetic cut. The submaxillary has not pre- 

 viously been secreting. Sympathetic stimulated by tetanic 

 shocks. Secondary coil 15. Readings every 10 seconds in 

 millimeters as before. The saliva was extraordinarily viscid. 

 Total stimulation 2 minutes, 40 seconds. Latent period ^5 

 seconds. 



Amount of secretion : o, o, o, o, 5, ;, 7, 5, 5, 5, 4, 5, 5, 4,4, 

 3; off, 3, I, o. 



If secretion can begin after 42 seconds, and endure for two 

 minutes, during a period of vascular constriction, as was the 

 case in this experiment, it can hardly be assumed that vaso- 

 constriction is the cause of the normal failure of that secretion 

 within twenty seconds. 



Heidenhain seems to have overlooked the fact that a sympa- 

 thetic secretion may be obtained after cutting off the blood 

 supply, at least five minutes after the chorda becomes inopera- 

 tive. He referred the quick loss of the chorda's power in these 

 experiments, to the suffocation of the gland cell.* If the loss 

 of the chorda's secretory power is due to the paralysis of the 

 gland cell by suffocation, the sympathetic must cause secretion 

 in some other way than action on the cell, since this nerve causes 

 a normal secretion long after the chorda has been paralyzed. 



The quick gush of saliva and its abrupt cessation, as well as 

 the anomalous cases represented by Experiment III, clearly indi- 

 cate a muscular mechanism of secretion. They are probably to 

 be explained as follows : On sympathetic stimulation the ducts 



■^Heidenhain, R. Hermann's Handbuch der Physiologic V, p. 46: "Die 

 Ursache der Verlangsaniung der Absonderung bei hochgradiger Gefassverengerung 

 oder Gefassverschluss liegt nicht in dem Sinken des Capillardruckes, sondern in der, 

 mit der kiinstliche Anamie der Driise verbundenen Verlangsamung des Blutstromes, 

 bei welcher sich das Secretions Material, und namentlich der Sauerstoff fur die 

 Driisenzellen allmalig erschopft so dass der secretorische Apparat erstickt. ' ' 



