90 STUDIES OF ANIMAL TYPES 



The mouth is continued posteriorly by a funnel-shaped 

 chamber, the pharynx. The small end of the pharynx leads 

 directly into the gullet, or esophagus. In the floor of the 

 pharynx, just before reaching the gullet, is an opening, the 

 glottis, which leads into the windpipe. The glottis is guarded 

 by an erect flap of cartilage, the epiglottis. The epiglottis is 

 raised when the animal breathes, but is closed down when 

 food is swallowed so that it can pass directly on into the 

 gullet. 



Body. The legs must now be fastened down. Extend 

 the hind ones backward and the front ones forward, with 

 the rabbit on its back, and tack them to the board. Slit 

 the skin from front to rear, peal it off, and turn to the sides 

 out of the way. Note the ribs in front, inclosing the thorax; 

 also the soft abdomen to the rear of the thorax. Cut the 

 ribs off along each side of the animal, and remove them 

 entirely, thus exposing the cavity of the thorax, being care- 

 ful to injure none of the contained organs. 



Note the diaphragm, a thin muscular partition dividing 

 the thorax from the abdomen. What is its shape ? Which 

 cavity is the concave side toward, and which the convex 

 side ? Note the liver close against the posterior side of the 

 diaphragm. Note the lungs in the thorax on the anterior 

 side of the diaphragm. What color are they? Lift them 

 in the hand. Are they light or heavy ? Why ? They are 

 commonly called " lights." What lies between the lungs? 

 What is the shape of the heart ? Which way does its small 

 end point? The heart lies within a membranous pouch 

 called the pericardium. Note that the cavity of the thorax 

 is lined with a thin, delicate membrane known as the pleura. 



Return to the gullet and follow it to the stomach. What 

 shape is the stomach? How does it lie? Estimate the 



