Pisces. 



157 



the anal opening. As 

 the perch is carnivorous, 

 we should naturally ex- 

 pect a relatively short in- 

 testine. In the anterior 

 part of the body cavity 

 lies the liver. On its 

 posterior surface is the 

 bile sac, which may be 

 greenish or yellowish, 

 or, if empty, have little 

 color. It is then hard to 

 discover, and appears 

 like a small worm-shaped 

 appendage to the liver. 

 A duct conveys the bile 

 into the intestine. 



Circulatory System of 

 the Perch. The heart 

 of "the perch is almost 

 literally "in his throat." 

 The heart is in a sepa- 

 rate cavity, the pericar- 

 dial chamber, with a 

 firm partition between it 

 and the main body cav- 

 ity. The heart consists 

 of three parts, through 

 which the blood passes 

 in order from behind. 

 The venous sinus re- 

 ceives the blood from all 

 parts of the body ; from 



