DIGESTION IN THE SMALL INTESTINE. 391 



drawn from the bile-duct, and after having remained some time in the 

 gall-bladder : 



2. The Secretion of the Bile. In contradistinction to the saliva and 

 gastric juice, the secretion of bile appears to be continuous: even during 

 prolonged abstinence, though reduced in amount, it is not suppressed. 

 Food exercises a marked influence on the quantity and composition of 

 the bile, every meal producing a maximum increase in the amount of 

 secretion which is reached between three and five hours after the com- 

 pletion of the meal. It then returns gradually to its original quantity, 

 to be again subjected to a second increase, which occurs between thir- 

 teen and fifteen hours afterward. This increased flow of bile, it will be 

 noticed, co-exists with the discharge of the contents of the stomach into 

 the small intestine, and it would appear, as has been determined experi- 

 mentally, that the application of the acid to the intestinal surfaces causes 

 a discharge of bile by causing reflex contraction of the bile-ducts and 

 gall-bladder. 



Since in the herbivora eating and digestion are almost continuous, 

 the amount of bile secreted is much larger than in the case of the 

 omnivora and carnivora. The total amount has been estimated to be 

 about five hundred to six hundred cubic centimeters in twenty-four hours, 

 or fifteen grammes of bile with half of one per cent, of solids per kilo of 

 body weight. In the horse the amount excreted in twenty -four hours is 

 about five to six kilos. In dogs, the secretion is most active after a meal 

 of meat, a diet of fat, however, greatly reducing the amount of this secre- 

 tion. According to Bidder and Schmidt, for every kilo of body weight 

 each hour the 



Sheep secretes . ' . . . 1.059 grammes of bile. 



The dog " . . . 0.824 



The cat " ." . . . 0.608 



The rabbit " . . 5.702 



