104 THE WORK OF THE DIGESTIVE GLANDS. 



the beginning of the secretion. When the flow at length commenced 

 it was very scanty. In the space of two to three hours, instead of the 

 usual lOc.c. to 15 c.c. we collected only 3 c.c. to 5 c.c. per hour, and 

 it was very much later when the normal quantities appeared. 



A similar curve of secretion was obtained when the fat was intro- 

 duced into the stomach immediately after the meal of flesh. The only 

 difference consisted in this, that here the secretion began with normal 

 energy at the usual time after feeding, and only later did the inhibitory 

 influence make its appearance. Finally, the same results were obtained 

 when the dog was given fat mixed with flesh to eat. In these instances 

 (experiments of Dr. Lobassoff), besides the diminution of the juice, a 

 lowering of its digestive power was also observed. I give here an 

 example of one of these experiments, and also by way of contrast I give 

 the normal flow after a meal of flesh without fat. 



Normal secretion after a meal of 400 grins, of flesh : 



Hour. Quantity of juice. Digestive power. 



1st ... 17'8 c.c. ... f>-2r> mm. 



2nd . . 13-8 ... 4-5 



3rd . . . 12-0 ,. 3-75 



4th ... 8-5 ... 3-38 



Secretion, from the same ration of flesh, given after 75 c.c. of olive 

 oil had been for one and a half hours in the stomach : 



1st ... 4-3 c.c. ... 4-25 mm. 



2nd . . . 5-3 ... 3-0 



3rd ... 4-5 ... 1'75 ., 



4th ... 3-8 ... T75 



A new and very striking fact is here before us. Fat depresses 

 that is, inhibits the normal energy of the secretory process. How is 

 this effect to be interpreted ? When one reflects upon our experimental 

 arrangements, and remembers that the secretion was collected from the 

 gastric cul-de-sac, it might be explained in two ways. Either the fat 

 hinders the secretion directly in a mechanical way for example, by 

 covering over the mucous membrane of the stomach and preventing the 

 excitation of its nerve endings or else indirectly, by reflexly stimu- 

 lating the inhibitory nerves of the glands, or the inhibitory centres of 

 those nerves. After a careful examination of all the facts, we are 

 compelled to adhere to the second hypothesis ; for, as previously 

 shown, the secretory activity after a meal of flesh always begins with 

 the psychic juice that is to say, with a flow of central origin, and it 

 is precisely this secretion, above everything, which is inhibited by the 

 fat, as may be clearly seen from the experiment quoted. 



