ORGANS OF THE MAMMALIA. 



107 



And so in its turn, the process of digestion would cease 

 with the want of action in the heart, and brain, so that 

 all these functions are performed as it were in a circle, 

 each one being dependent on the other. In one view, 

 each of these functions may be considered as subservi- 

 ent to the other, while in another view, each is seen to 

 be entirely dependent on the other. 



Plan of the most important Viscera. A connected 

 view of the most important visceral, and vital organs are 

 represented by Fig. 74. This is a side view, showing 

 Fig. 74. 



the natural situation of the parts as they are placed in 

 quadrupeds, but may be considered as applying to the 

 human species without any material change. 



In the explanation of this view we will begin with the 

 passage of the food to the stomach. The esophagus o, 

 is a muscular tube leading from the mouth to the stom- 

 ach, and through which the food passes, to the latter or- 

 gan. Of the stomach s c, is the part nearest the heart, 

 and is called the cardia, or cardiac portion, while the 

 opposite part is termed pylorus. This leads to the in- 

 testinal tube marked i, i. The mesentery m, connects 

 the latter part with the back, the use of which will be 

 explained directly. The enlargement r, is the recepta- 



