134 ZOOLOGY. 



cation could be made with a different basis. Gasteropod shells, illustrating 

 varieties of the same and different species; beetles, butterflies; grass- 

 hoppers; or even books of diverse shape, binding and contents may be 

 used. 



8. Can you suggest any cause for the degeneracy of parasites? 



9. Cite instances from your own observation in which animals use the 

 leap or spring in capturing prey or escaping enemies. Why is it a pecu- 

 liarly advantageous adaptation? 



10. Cite instances of the food-storing instinct, with all observed details. 

 What is the most remarkable fact about them? How is it useful? 



11. From reading and observation would you say that there is any 

 definite relation between the instinct for home-building and parental care? 



12. Study sleep among animals. What is its relation to rest? Is it 

 found in the lower animals? To what is sleep an adaptation? When 

 does sleep commonly occur among animals? Why? Do plants show any 

 sleeping qualities? 



13. What are the principal geographical faunas recognized by zoolo- 

 gists. Enumerate the more important means by which dispersal of ani- 

 mals from one region to another occurs. What are the chief barriers to 

 the dispersal of land animals? of aquatic animals? 



14. Study the different authors to which you have access, as to the 

 significance of the terms species and variety (or sub-species). 



15. What were the older views concerning the "fixity" or invariability 

 of species? 



16. What are the different views of the " Origin of Species," as based 

 on the views of the meaning of species? 



17. What is the essential difference between the theories of "natural 

 selection " and " definite variation " as explaining adaptation of organisms 

 to their environment? 



18. What additional ideas are introduced by the "mutation" theory 

 of De Vries? 



