PHYSIOLOGY OF ALIMENTATION. 



curve B that obtained when the same amount of food is 

 introduced into the stomach directly, and curve C the result 

 when sham feeding with the same is indulged in. D is a 

 synthetic curve produced by adding B and C and approxi- 

 mates closely curve A. As can readily be seen, the introduc- 

 tion of food into the stomach directly does not lead to as rapid 

 or as great a secretion of gastric juice as does the normal 

 process of feeding. But if the quantities obtained by intro- 

 ducing the meat into the stomach be added to those ob- 

 tained by sham feeding a curve almost identical with the 

 normal results. 



The importance of the psychic element in gastric digestion 

 can be demonstrated still more strikingly by the following ex- 

 periment of LOBASSOFF on two cesophagotomized dogs pos- 

 sessing ordinary gastric fistulae. If a definite number of 

 pieces of meat threaded on strings be introduced directly into 

 the stomach of one dog while its attention is being distracted 

 by patting and talking kindly to it, and an equal number of 

 pieces are introduced into the stomach of another dog, but 

 during the process a vigorous sham feeding is kept up, the 

 following differences are noted. Two hours after 25 pieces 

 weighing 100 gms. in all had been fed to each of the dogs, 

 the dog without sham feeding had digested 6.5 percent, 

 the one with sham feeding for eight minutes, 31.6 percent, 

 as shown by subsequent weighing of the undigested food ex- 

 tracted from the stomach. In another experiment, in which 

 the meat had remained for five hours in the stomachs, 58 

 percent had been digested without sham feeding, wl^ile 85 

 percent had been digested with sham feeding. These figures 

 leave no room for doubt of the great importance to be attached 

 to the eager desire for food, in other words to the appetite. 



6. Other Excitants of Gastric Secretion. It must not 

 be believed from the foregoing that the appetite is the only 

 excitant of gastric secretion. This is shown not only by 

 the observation that a secretion of gastric juice occurs when 

 the psychic element is allowed to play no part at all, as 



