I 



Digestion — The Intestines 115 



tines are divided into large and small, the latter being 

 from three to four times as large as the former. 



When the food leaves the stomach, it enters the 

 small intestines. At this point it is only partially 

 digested. The fats are probably so far unchanged and, 

 without doubt, the larger proportion of the proteids 

 and carbohydrates that are susceptible of solution is 

 still in the original condition. Hardly has this par- 

 tially dissolved material passed into the small intes- 

 tines before it comes in contact with two new liquids 

 which are poured upon it simultaneously or nearly so; 

 viz., the bile and the pancreatic juice, and the changes 

 which began in the mouth and stomach, together with 

 others which set in for the first time, proceed vigor- 

 ously. 



The bile has its source in the liver. It is a secre- 

 tion of this organ, and after elaboration it is stored in 

 a small sac attached to the liver which is called the 

 "gall bladder," and from which gall is conveyed to 

 the intestines through a duct opening very near the 

 orifice leading out of the stomach. Bile is a liquid 

 varying when fresh from a golden red color in man 

 to a grass -green or olive -green in certain herbiverous 

 animals. It is slightly alkaline, bitter to the taste 

 and without odor. The specific and characteristic con- 

 stituents of the bile are two acids, glycocholic and 

 taurocholic, that are combined with sodium and are 

 associated with two coloring matters, bilirubin and 

 biliverdin. Numerous other compounds are present 

 in very small proportions, such as fats, soaps and min- 

 eral compounds, but they appear to have no important 



