FISH. 



I. External Characters. 



1. Make an outline sketch showing the fins, 



orifices, etc. 



2. Find the operculum. Lift it up and find : 



3. The gills. How many are there? How many 



slits between the gills (gill-clefts) ? 



II. Abdominal Viscera. 



Cut through the body-ivall on loth sides along the 

 lines indicated in the diagram.* Remove the 

 portion of body -wall thus cut out. 

 Observe : 



1. The liver, a conspicuous brownish lobed organ. 



Lift it up to see : 



2. The gall-bladder. 



3. The hepatic veins, passing anteriorly from 



the liver. 



4. The stomach, partly concealed by the liver. 



5. The intestine, passing posteriorly from the 



stomach with one or two turns to the anus. 



* An outline-diagram of the fish with lines to mark places for 

 cutting : 



1. Antero-posteriorly : parallel and slightly ventral to the lateral 



line. 



2. Dorso-ventrally from the median ventral line to meet the 



first cut: 



(a) An inch in front of the anus. 



(6) Obliquely just posterior to the pectoral and pelvic 

 girdles. 



113 



