32 Feeds and Feeding. 



smell of food are designated by Pawlow as "psychic secretions." 

 For example, when a dog was given a false meal, and the swallowed 

 food fell out of the fistula or opening in the throat and back into 

 the dish out of which the dog was eating, the stomach would never- 

 theless pour forth its fluids (psychic secretions), as tho the food 

 had reached it. The more eagerly the dog ate his false meal the 

 greater was the amount of gastric secretions, and the richer they 

 were in both acid and pepsin. The gastric secretions were freest 

 and strongest with that food which was liked best, and food given 

 in small portions called forth stronger juices than when the whole 

 ration was given at one time. 



It was found that in character and proportion the digestive fer- 

 ments adapt themselves to the nature of the food. When the meat 

 diet of a dog was changed to one of milk and bran, the protein- 

 digesting enzymes of the pancreatic juices diminished, while the fer- 

 ments which act on starch were increased. Pawlow 's studies lead 

 to the conclusion that the gastric and pancreatic glands are guided 

 by a form of instinct, so that they pour out their juices in a n- 

 ner which corresponds quantitatively and qualitatively, in a 

 ure, to the amount and kind of food consumed. He believes that in 

 time it will be found that there are specific stimuli or excitants in 

 the food itself, possibly produced after it has entered the alimen- 

 tary tract, the purpose of which is to excite and draw forth that 

 form of secretion which is best suited to digest the particular kind 

 of food then in the stomach. 



The studies of Pawlow, here barely touched upon, point plainly 

 to the great basic fact that digestion, appetite, and palatability are 

 associated with each other, and should be studied together and not 

 separately. With palatability, appetite, and digestion inter-related 

 and resting on so fundamental and profound a basis, the prudent 

 stockman will always give due heed to the preferences of his ani- 

 mals as to kind and quality of food, as well as to its preparation 

 and administration. 



48. Palatability. So vague and illusive is the subject of the pal- 

 atability of food that it would be a waste of space to discuss it at 

 any length in this work. "What is one man's meat is another man's 

 poison" is an old saying, to which might be added, "and what is 

 one man's meat today may be his poison tomorrow ;" for desire, 

 appetite, and digestion are not the same with any given individual 

 at all times and under all circumstances. Even with farm animals 

 palatability is greatly influenced and controlled by familiarity and 



