MOVEMENTS OF THE ALIMENTARY CANAL 431 



valve prevent. The result of this movement is a churning and 

 mixing of the contents whereby the absorption of the last useful 

 materials, including the water, is promoted. As the large in- 

 testine is filled more and more from the small, some of its contents 

 are crowded, in spite of the antiperistalsis, into the descending 

 colon, where regular peristaltic waves carry them on to the sigmoid 

 flexure and the rectum, whence they are discharged from the Body. 



