THE GENEIIAL ANIMAL FUNCTIONS 9 1 



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 yourself rigidly 

 to your 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 statocysts 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 ? 



16. Discover what glands are known to produce internal 

 secretions (hormones). Where are these located? What, in 

 general, are the effects of each of these secretions ? 



