108 THE BIOLOGY OF THE ANIMAL 



brane of which they are composed. Are the 

 pouches distensible ? To what are they attached ? 

 How does the cardiac compare in size with the 

 pyloric portion? Do you find any ingested food 

 in the cardiac portion? If so, of what does it 

 consist ? Do you find any structures which could 

 serve to grind hard food ? Do jo\x find any speci- 

 mens in which a part of the cardiac portion pro- 

 trudes through the mouth? Look for the re- 

 tractor muscles of the cardiac pouches. How 

 many are there ? What is their shape ? Length ? 

 To what are they attached ? Look for the pro- 

 tractor muscles. Compare them with the re- 

 tractors. What is the position of the pyloric 

 with reference to the cardiac portion? Do you 

 notice any difference in the character of its wall ? 

 Notice the very short passage, oesophagus, lead- 

 ing from the mouth to the stomach. The shape 

 of the various portions of the stomach may be 

 well seen by proceeding as follows : Kemove the 

 roofs from all the rays, but leave the roof of the 

 disk untouched. Separate the latter along the 

 inter -radial partitions, divide the ducts of the 

 hepatic coeca, remove the coeca from the body, 

 turn the latter upside down, and pour water into 

 the mouth. The water will distend the stomach 

 and show its shape. 



Near the centre of the aboral side of the py- 

 loric portion of the stomach find 



d. The intestine. — What is its shape ? Length ? Look 

 for the opening, anus, to the exterior. 



Near the intestine look for a brownish saccu- 

 lated organ, 



