94 DIGESTION. 



digested by the gastric juice. From whatever source they 

 are derived, vegetable or animal, they are all transformed 

 into the same digestive product, called albuminose. This is 

 very soluble in water, and is readily absorbed by the blood- 

 vessels of the stomach. After a longer or shorter time, 

 varying from one to five hours, according to the individual 

 and the. quantity and quality of his food, the stomach will 

 be found empty. Xot only has the digested food passed 

 out, but also those substances which the stomach could 

 not digest or absorb have passed little by little through 

 the pylorus, to undergo further action in the intestines. 

 At the time of its exit, the digested food is of a pulpy 

 consistence, and dark color, and is then known as the chyme. 



31. The Intestines. The intestines, or "bowels,"' 

 are continuous with the stomach, and consist of a fleshy 

 tube, or canal, twenty-five feet in length. The small 

 intestine, whose diameter is about one inch and a half, is 

 twenty feet long and very tortuous. The large intestine is 

 much wider than the former, and five feet long (Fig. 2). 

 The general structure of these organs resembles that of the 

 stomach. Like it, they are provided with a mucous mem- 

 brane, or inner lining, whence flow their digestive juices; 

 and, just outside of this, a muscular coat, which propels 

 the food onward from one point to another. 



32. Moreover, both the intestines and stomach are envel- 

 oped in the folds of the same outer tunic or membrane, called 

 the peritoneum. This is so smooth and so well lubricated, 

 that the intestines have the utmost freedom of motion. 

 In the small intestines, the work of digestion is completed, 

 the large intestine receiving from them the indigestible 

 residue of the food, and in time expelling it from the body. 



33. Intestinal Digestion. As soon as the food 

 passes the pylorus and begins to accumulate in the upper 



31. What are the intestines? The small intestines? The large intestines? 

 Their structure? 



32. Peritoneum ? The work of digestion ? 



33. The presence of food in the intestines ? ,Bile ? 



