DIGESTION 



377 



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it will digest in a given time. ' Bread juice ' is much stronger 

 in ferment than ' meat juice/ and ' meat juice ' somewhat 

 stronger than ' milk juice ' (Fig. 147). But ' meat juice ' has 

 a higher acidity than ' bread juice,' ' milk juice ' being inter- 

 mediate. These differences do not necessarily indicate that the 

 gastric mu- 

 cous mem- 

 brane re- 

 sponds in a 

 specific way 

 to each kind vj 

 of food sub- ^ 

 stance, as * 

 suggested 3 

 by Pawlow. 

 They may 

 depend on 

 several cir- 

 cumstances, 

 andparticu- 



Flesh, 200 grm. 



Bread, 200 grm. 



Milk, 600 c.c. 



FIG. 146. RATE OF SECRETION OF GASTRIC JUICE WITH 

 DIETS OF MEAT, BREAD, AND MILK (PAWLOW). 



larly on this 



that the quantity, though not the quality, of the psychical 

 or ' appetite ' juice is related to the relish with which the 

 animal eats the food. The products formed in the digestion of 

 the different foods by the psychical juice may therefore be 

 different in nature and amount, and thus the quantity of the 

 gastric hor- 

 mone which 

 determines 

 the second- 

 ary secre- 

 tion may 

 vary with 

 the food. 



The young 

 mamm al, 

 like the 

 adult, se- 

 cretes gas- 

 tric juice be- FlG - 

 fore the food 



Flesh, 200 grm. Bread, 200 grm. Milk, 600 c.c. 



147. DIGESTIVE POWER OF GASTRIC JUICE (PAWLOW). 

 The digestive power of the juice, as measured by the length 



,1 of the protein column digested in Mett's tubes, is represented 

 ' hour by hour, with diets of flesh, bread, and milk. 



stomach. 



In puppies from one to eighteen days old sham feeding (sucking 

 the teats of the mother after an cesophageal fistula has been 

 made in the younger animals and a double cesophageal and 



