PROBLEM 136 161 



come out? What gas is in the water? How might the fish use 

 this gas? How might this gas come in contact with the gills? 



Conclusion. — Tell just how a fish breathes, writing a paragraph 

 in explanation and illustrating with a diagram. 



Problem 134 : To study food getting by the fish. 



Material. — Live fish. 



Method. — Watch the fish to see if it will eat. Remember 

 what you know about catching fish. 



Observations. — Do fish see or are they made aware of the 

 presence of food by other means ? Do fish have teeth ? Do they 

 chew their food ? Give uses of teeth. How does the fish's means 

 of obtaining food compare with ours ? 



Conclusion. — Write a paragraph telling how a fish gets its 

 food. 



Problem 135 : To study the sense organs of the fish. 



Material. — Specimens of fish. 



Method. — Study the external sense organs of the fish. What 

 are they? 



Observations. — What shape are the eyes? Does a fish move 

 its eyes? Describe any movement. A fish is very nearsighted 

 owing to the shape of the eye. Find two nostril holes. These 

 lead to little pits in which are located the nerves of smell. Does 

 a fish breathe through its nose ? Find a distinct line running down 

 the side of the fish. This is called the lateral line and contains 

 organs of sense. The ears of the fish are out of sight in the head 

 and are largely used for balancing. 



Conclusion. — Write a paragraph telling how the fish is fitted 

 with sense organs. Compare its vision, sense of smell, and power 

 of hearing with your own in respect to keenness. 



Drawing. — Make a side view of a fish. Label all the struc- 

 tures we have discussed. 



Problem 136 : To study some of the internal organs of a fish. 

 Material. — Preserved specimens with under body wall cut 

 away. 



HUNTER LAB. PROB. — 11 



