218' THE DOG-FISH 



1. The liver is a very large solid organ of a brownish yellow 



colour, attached by a median suspensory ligament to 

 the anterior wall of the abdominal cavity. It consists 

 of two lobes of about equal size, which are united 

 in front, and extend back along the sides of the ab- 

 dominal cavity for the greater part of its length. 



2. The stomach is a wide U-shaped tube lying between the 



lobes of the liver, and extending about two-thirds the 

 length of the abdominal cavity. 



3. The spleen is a large brownish red body attached to the 



loop of the stomach, and sending a long narrow lobe 

 along its distal limb. 



4. The intestine is a wide and nearly straight tube, running 



along the right side of the abdominal cavity from the 

 stomach to the cloaca. 



5. In the female the ovary is single, and attached by a 



delicate median fold of peritoneum to the wall of the 

 abdominal cavity. The contained ova give its 

 surface a tuberculated appearance. 



In the male the testes are a pair of elongated 

 solid bodies of a whitish colour, lying along the 

 dorsal region of the anterior two-thirds of the ab- 

 dominal cavity. Their hinder portions fuse together. 



6. The peritoneum is the smooth membrane lining the 



abdominal cavity, and reflected downwards from the 

 mid-dorsal line as a double sheet — the mesentery — 

 which covers the alimentary canal and other viscera. 

 The mesentery is well developed at the hinder 

 end of the abdominal cavity, but is interrupted by 

 one or more large fenestra opposite the greater part 

 of the length of the intestine. 



7. The kidneys are covered by the peritoneum, but can be 



recognised as a pair of slightly elevated longitudinal 

 ridges, one on each side of the mid-dorsal line of 

 the abdominal cavity, and extending nearly its whole 

 length. 



