I hope you have now been convinced of the great importance which is to be attached to the passage of food through the mouth and œsophagus, or, in other words--and this, according to our former experiences, means the same thing--to the eager desire for food. Without this longing, without the assistance of appetite, many forms of food-stuffs which gain entry to the stomach remain wholly devoid of gastric juice. Others, it is true, excite a secretion, but the juice poured out is scanty and weak. It is only later, when we have still more fully recognised the conditions 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 comprehensive 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 œsophagus. 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 mm. 10 20.0 ” 8.0 ” 10 13.5 ” 6.8 ” 10 11.0 ” 7.5 ” 10 8.5 ” 8.1 ” 10 6.5 ” 9.0 ” 20 13.5 ” 7.4 ” 20 11.0 ” 7.2 ” 20 7.0 ” 7.2 ” 20 11.5 ” 6.8 ” 20 11.0 ” 6.5 ” 30 6.5 ” 7.6 ” 20 5.5 ” 7.2 ”