Pelecypoda. 



stomach. On each side of the stomach is a large, greenish, 

 digestive gland, often called the liver, whose secretion 

 passes into the stomach. From the stomach the intestine 

 passes downward and backward, making one or two coils 

 in the abdomen and foot, then passes upward back of the 

 stomach, near the dorsal margin ; it then turns posteriorly, 

 parallel to the dorsal margin, passes through the ventricle 



Digestive 

 gland 



Anus 



Intestine 



FIG. 71. DIGESTIVE AND EXCRETORY ORGANS OF A CLAM. 



of the heart, over the posterior adductor muscle, just back 

 of which it ends, thus discharging the refuse of digestion 

 where the outgoing current of water will catch it and 

 sweep it out of the body through the dorsal siphon. The 

 digestive tube is hard to trace in a fresh specimen, less 

 difficult in one which has been boiled or hardened in 

 alcohol. The whole tube may be injected with a colored 

 starch injection and thus readily followed. In the fall 

 the intestine is often found to contain a cylindrical body of 



