ON RESPIRATION. il9 



psc'res bnek again in conjunction with that 

 ^vhich is returned from the lungs. The inflation 

 r this cavity gives to the animal that animated 

 appearance observable upon various occasions. 



In other respects, the organs of respiration 

 differ but little from those of the human being:, 

 except that the diaphragm i. Diiich more mus- 

 cular, and situated more obliquely, by whicii 

 means the stomach lies below it, although the 

 body is in an horizontal position. This incli- 

 nation of the diaphragm renders the resistance 

 of the stomach and intestines less powerful than 

 if it were placed in a more perpendicular direc- 

 tion. When the lungs collapse, this diaphragm 

 is slackened, but in the act of inspiration it is 

 tightened so as to force back the contents of tlie 

 abdomen, by which means the capacity of the 

 chest is enlarged. This is performed partly by 

 its own muscular contraction, and partly by the 

 expansion of the ribs, whereby the lateral 

 I 4 points 



