84 THE WORK OF THE DIGESTIVE GLANDS. 



gastric juice. Others, it is true, excite a secretion, but the juice poured 

 out is scanty and weak. 



It id only later, when we have still more fully recognised the con- 

 ditions upon which the secretory work of the gastric glands depends, 

 that we shall be able to grasp the meaning of these facts in a more com- 

 prehensive manner. For instance, why does bread brought unnoticed 

 into the stomach of the dog cause no secretion for hours, while flesh 

 tolerably soon (after twenty to forty minutes) provokes this act? This 

 will be explained in the next lecture ; now, however, we must consider 

 other questions. 



How long does the after-effect, the echo of the first impulse to the 

 secretory nerves of the stomach, continue to last ? How long does 

 appetite juice continue to flow after the normal act of eating, which, 

 especially in the case of animals, is not of long duration ? We have 

 already determined many times, not only on our dog with the isolated 

 stomach, but also on other animals, how long the after-effect of sham 

 feeding is continued. 



Here, for example, is an experiment from the article of Professor 

 Ssanozki which deals with the point. The dog had a gastric fistula and 

 also an opening leading into the esophagus. After a sham feeding 

 of five minutes the secretion began, and was continued as follows : 



Time in minutes. Quantity. Digestive power. 



10 . . . . 25-5 c.c. ... 8'1 nun. 



10 .... 20-0 ... 8-0 



10 . . . 13-5 .-.. <i-8 ,, 



10 .... 11-0 ... 7-r> 



10 .... 8-5 ... 8-1 ., 



10 .... 6-5 ... ICO 



20 .... 13-5 ... 7-4 



20 .... ll'O ., ... 7-2 



20 . . . . 7-0 ... 7-2 



20 .... ll-o ... C.-S 



20 . . . . ll-o <>:> 



30 .... r>-5 ... 7-r, 



20 .... 5-5 ... 7-2 .. 



The effect, therefore, even after a short period of sham feeding, 

 stretches over a length of time. Naturally the same holds good for the 

 taking of food in the normal way. One must, however, bear in mind 

 that in sham feeding, with all the force and reality of a hunger sensation 

 not satisfied ; the eager desire for food ; the effective agency, becomes 

 more and more accentuated, and therefore the secretory influence is 

 prolonged and more powerful. In normal feeding, however, the 

 quelling of the longing, the feeling of satisfaction which, as is well 

 known, sets in long before the termination of the digestive period 



