34 LABORATORY WORK. 



injured. This lays open the peritoneal cavity (coelom). 

 Insert a blowpipe into the gullet and inflate the stomach. 

 Is there any sharp boundary between it and the intestine? 

 Is the intestine more or less coiled than in bony-fish or 

 dogfish? Is it of the same size throughout? How is it 

 suspended? 



Does the liver cover the stomach? Turn the liver for- 

 ward and look for the greenish, spherical gall-bladder and 

 the light-colored, lobulated pancreas. Do you find ducts 

 from either of these to the intestine? Farther back, in 

 the mesentery, near the enlarged portion (rectum) of the 

 intestine, is the red spleen. At the posterior portion of the 

 peritoneal cavity is the thin-walled urinary bladder. With 

 what is it connected? 



Draw the digestive organs, showing the position of the' 

 deeper structures by dotted lines. 



Turn the intestines, etc., out of the body, exposing the 

 reproductive organs and kidneys. These will differ in 

 their appearance in the two sexes. 



In the male a yellowish, rounded body (testis) occurs on 

 either side of the median line, and just in front of each 

 are the yellowish, lobulated fat-bodies. Beneath (dorsal to) 

 the testes are the reddish-brown kidneys, each having on 

 its ventral surface a yellowish or golden adrenal gland. 



What is the shape of the kidneys? Are the testes and 

 kidneys connected in any way? Do you find the ducts 

 (ureters) leading back from the kidneys? Where do they 

 end? 



In the female, the ovaries, crowded with dark-colored 

 eggs, occur in the place of the testes, their size depending 

 upon the season. Near them are the coiled oviducts. 

 Trace these forward and back to their terminations. Do 

 you find the fat-bodies? Do kidneys and adrenals corre- 



