THE STORY OF DIGESTION 41 



body where the liver is situated. Roughly speaking, 

 if we take the stomach as the centre of the organs 

 contained in the abdomen or belly, we find the liver 

 (Fig. 11) lying to the right, the spleen to the left, and 

 the sweetbread or pancreas below and in front of the 

 stomach. The stomach, like the rest of the digestive 

 system, has three coats or coverings. There is first 

 of all a somewhat tough outer coating (serous coat) 

 giving shape to the tube. The middle coat is a 



Fig. 10. THE STOMACH 



Showing interior and commencement of bowel. 

 The sweetbread duct is shown opening into the bowel. 



muscular coat composed of involuntary muscular 

 fibres, or in other words of fibres which are not 

 directly under the command of the will as are the 

 muscles of arms, legs, and other parts of the body. 

 The function of this muscular layer of the digestive 

 tube is naturally to propel the food along its course, 

 whilst in the case of the stomach the duty of the 

 muscular coating is to cause movements of the 

 stomach to take place so that the food will be made 



