THE FISH. 73 



border of each side of the upper lip is the pre-max- 

 illary; note its extension backward on the middle of 

 the snout; observe the fine teeth on it. Observe 

 their size, shape, arrangement, and the direction in 

 which they point. 



The paddle-like bone back of the pre-maxillary is 

 the maxillary. 



The bone on each side of the lower jaw is the 

 dentary. Which of these bones bear teeth? Open 

 and shut the mouth repeatedly, watching the move- 

 ments of these parts, and their relations to each 

 other. 



Compare the perch or bass with the sucker in the 

 movements of the mouth parts. 



Back of the pre-maxillary, in the front part of the 

 roof of the mouth, is a patch of teeth, borne on a 

 bone called the vomer ; extending backward from 

 the vomer, on each side of the roof of the mouth, are 

 rows of teeth on the palatine bones. 



Examine the short tongue; feel its surface with 

 the tip of the finger, or scrape it with the head of a 

 pin ; examine also the whole of the inside of the 

 mouth, to see if there are more teeth than those 

 mentioned. Can a fish taste? 



Note the shape and position of the eyes; with the 

 handle of the forceps press on the eye at various 

 points near its margin, to see its range of motion; 

 watch the roof of the mouth while pressing the eye, 

 also press outward on that part of the roof of the 

 mouth nearest to the eye. Compare the eyes with 

 human eyes. Are eyelids present? Observe a thin 

 bone imbedded in the skin immediately in front 



