100 GENERAL BIOLOGY. 



to make the bile pass to the duodenum. 

 Look now for the bile-duct. 

 (/) The fat bodies : long slender yellow masses 

 on each side, attached to the dorsal 

 wall of the body-cavity at about the 

 level of the posterior border of the liver. 

 In different specimens they vary much 

 in size. 

 Identify : 



(k) The reproductive organs. 

 IY. The Circulatory Organs. 



Open the per icar dial cavity, using great care not 

 to injure the anterior abdominal vein which 

 passes dorsally in the posterior wall of the 

 pericardium. 



1. Examine and sketch the heart, showing its 

 parts : 



(a) The auricles : dark colored and with thin 



walls. 



(b) The ventricle : of paler color and conical. 



(c) The truncus arteriosus: arising from the 



anterior side of the ventricle, passing 

 obliquely forward and dividing into two 

 large branches. 



Turn the apex of the heart forward and note 

 on its dorsal side : 



(d) A darker triangular-shaped region, the 



sinus venosus. It is closely related to the 

 auricles, and receives the great veins. 



