ABDOMINAL ORGANS. 195 



Organs of the Abdominal Cavity. (Rabbit or cat.) 



1. Slit the skin in the middle line from the breast-bone to 

 the pelvis, and strip it well back to the sides. Observe the 

 thin Abdominal Muscles, which form the ventral wall of the 

 abdomen. Carefully slit this in the middle line from the pel- 

 vis to the breast-bone ; from the middle of this slit cut 

 outward on each side, and turn back the flaps. 



2. The lining of the abdomen is the Peritoneum ; draw 

 the tips of the fingers over it to learn its smoothness. 



3. Observe the coiled Intestine, noting any variations in 

 size, shape, or markings, but do not now move any part from 

 its natural position. In a recently killed animal the intes- 

 tines usually show a slow motion, like that of a mass of 

 earthworms, coiled and crawling over each other. This is 

 the Peristaltic motion, due to the shortening and relaxation 

 of the muscles in the walls of the intestines. This is always 

 a wave-like motion, proceeding from the anterior toward the 

 posterior end of the intestine. 



4. In the anterior part of the abdomen the dark-colored 

 Liver may be seen, overlapping the Stomach ; and in the hinder 

 part of the abdomen the Bladder may be seen, varying greatly 

 in size and appearance according to the state of distention. 



5. Pull the intestine backward, and make out the shape, 

 size, position, and color of the stomach. Care must be taken 

 in handling the liver. Its tissue is so delicate that it is 

 easily ruptured ; and the organ is so full of blood that enough 

 may soon escape to make the dissection unsightly, and to 

 obscure some of the organs. Do not touch the liver with the 

 dissecting instruments, not even with the handle of the scal- 

 pel ; and in handling it with the fingers, take care not to 

 lacerate it with the nails. Observe how the liver and stomach 

 fit together ; push the liver forward, and turn the stomach 

 back to find a white tube entering its anterior surface ; this is 



