1. Watch the fishes in the large aquarium and determine which fins are most used and how they are used (a) in swimming forward, (b) in swimming upward and downward, (c) in maintaining balance, (d) in remaining at rest, and (e) in guiding the movements of the fish. 2. What advantages are there to the fish (a) in the power to open and close the dorsal and anal fins, (b) in having no neck, and (c) in having a compressed form? 3. Enumerate the various ways by which the body of the fish is adapted to rapid movement through the water. _Feeding._ 4. What is the food of the fishes you are studying? Feed them and watch them eat. Why is the upper jaw often called a "lip"? What is the shape and size of the mouth when opened in feeding? Does the fish chew its food? Describe in detail the fishes' method of feeding. _Respiration._ 5. Identify the opercula and the gill openings. Watch the movements of the opercula and mouth, and determine what movements are concerned in breathing and their order. Describe in detail the circulation of water used in breathing and how it is caused. _Sense Organs._ 6. Identify the eyes, nostrils, and lateral line. How many nostrils are there and where located? What is the position and extent of the lateral line? 7. Describe the location of the eyes. What is the shape of the outer surface of the eyes? Why this shape? Can the eyes be moved, _i.e._ can they be rotated, rolled, or retracted? From what direction might an enemy approach without being seen? How would such an enemy be detected? _Protection._ 8. With what protective structures is the body covered? Do they hinder the movements of the fish? What are the advantages of the scale covering of fishes over the shell covering of grasshoppers or crayfishes? 9. In what other ways are the fishes you are studying protected against enemies? Since you cannot account for the red color of goldfishes on the basis of use to the fish, then how do you account for this bright color? _The Body._ 10. What is the symmetry of the fish? Into what regions is the body divided? _Summary of the study of the living fish._ Enumerate in one column the different adaptations which fit the fish for life in water and in a second column state the special purpose of each adaption. The External Structure of the Fish _Materials._ Freshly killed or preserved fish in dishes or shallow pans with enough water to prevent drying. Simple or compound microscopes, forceps, and a bristle. _Directions._ Examine the fins and identify the membrane and the supporting rods, or _rays_, of bone or cartilage. Notice how the ends of the cartilaginous rays keep the membrane from tearing. Investigate the scales as to their arrangement, number, and size. Remove a small patch of scales along the lateral line to find how they are attached, where the fish's color is situated, and how access to the sensory organs of the line is permitted. Examine a scale under the microscope.