82 ZOOLOGY. 



3. Compare the ways in which animals known to you cap- 

 ture and prepare their food for swallowing. What special 

 structures arise in connection with this function? 



4. Do animals have any power of storing food within the 

 body for future use? Compare with plants. 



5. Compare gills and lungs as to general form and arrange- 

 ment and see in what ways they appear to you to be suited to 

 their particular media, i. e., gills to water and lungs to the air. 

 Why might not the conditions be reversed? 



6. What seem to you to be the comparative advantages and 

 disadvantages of the exoskeleton and endoskeleton. 



7. Devices to accomplish locomotion in animals known to 

 the student. Find as many variations as possible. 



8. Select four animals, as diverse as possible, representing 

 each of the following conditions of locomotion : through the 

 air, through the water, on the earth, and through the soil. 

 Compare the problems which each must solve, and the organs 

 by which the work is accomplished. 



9. Compare known animals as to rate of locomotion. Do 

 you find a satisfactory explanation in any case? 



10. Let the student attempt to prove that the dog experi- 

 ences the same sensations which we have. Hold him rigidly 

 to his evidence. 



11. Report on the general differences between the eyes of 

 insects and of vertebrates, with a statement of their structure 

 and the work done by each. 



12. In what way could the otocysts possibly act as organs 

 to enable the animal to appreciate its position in space, and 

 thus maintain its equilibrium? 



13. What are the simpler facts connected with the process 

 of absorption or osmosis of dissolved substances in the body? 



14. Find in text-books of chemistry a fuller account of the 

 process of oxidation and why it results in a liberation of 

 energy. 



15. Demonstrate how a biconvex lens forms an image of 

 objects. Why inverted? 



