66 CHYLIFICATION. 



6. By the action of the gastric juice, the food is softened and 

 little by little changed into a thick, grayish pap, which is called 

 chyme. 



7. As soon as the chyme is formed, the pylorus relaxes and the 

 stomach begins to perform a series of*movements which, by de- 

 grees, push the alimentary mass towards this opening, and then into 

 the intestine. These movements consist in the successive con 

 traction of fleshy fibres which surround the stomach transversely 

 and which contract, one after the other from left to right. 



OF INTESTINAL DIGESTION, OR CHYLIFICATION. 



8. The chyme which issues from the stomach enters the intes- 

 tine where it serves to form chyle. 



9. The i/iti'?ti HC (page 67. Jig. 23,) is a long membraneous tube, 

 folded upon itself, which forms a continuation of the stomach 

 and which, by its opposite extremity, opens outwardly. It is 

 lodged in the abdomen, and is retained in its place by folds of 

 a very fine membrane called peritoneum, which lines the parietes 

 or walls of this cavity. The folds of peritoneum which connect 

 the intestines to the spine, bear the name of mesentery. 



10. The parietes of the intestine are furnished with fleshy fibres 

 which surround them, and which, by contracting successively, 

 push forward the matters contained within this tube. These 

 movements are called vermiform or vermicular, because they 

 resemble those of a worm when crawling. 



11. The length of the intestine is always very considerable, but 

 varies very much in different animals. It is remarked that in 

 those which are nourished by flesh exclusively, it is much shorter 

 than in those which live on vegetable substances : thus in the 

 lion, winch is essentially carnivorous, it is only three times the 

 length of the body ; while in man, who is omnivorous, its length 

 is about six or seven times that of the body, and in the sheep 

 which eats grass only, it is just twenty-eight times this length. 



12. The intestine is composed of two very distinct portions 

 the small intestine, and large intestine. 



I . . . . .-. ........ . .. ., 



6. What is chyme ? 



7. What takes place after the chyme is formed ? 



8. What is formed from the chyme ? 



9. Whai is the intestine? Where is it 1 dged ? What retains it in its place ? 



10. What arrangement enables the intestine to push forward substances 

 within it? 



11. In what class of animals is the intestine longest ? What is its length 

 in man ? 



