THE NERVOUS SYSTEM AND SPECIAL FUNCTIONS. 303 



reason of so large an increase of absorbing surface. 

 Such small part of the food mass as is not absorbed here, 

 passes out of the body by way of the rectum and the 

 anus. 



Such prepared food as is gathered from the alimentary 

 canal by the lacteals and papillate absorbents of the lining 

 wall, by way of the lymphatic conductors, is emptied into 

 the thoracic duct and then thrown into the blood circu- 

 lation, to be oxygenated in the lungs, much as the same 

 process is accomplished in man. 



