402 QUESTIONS, PROBLEMS, AND SUGGESTIONS 



8. Self-defense. — Name and trace all the means and modes of defense of 

 the eggs, the young, or of the adult invertebrate. 



9. Rivalry. — Trace all adaptations for rivalry by (1) battle, (2) song; 



(3) color, or other means. 



10. Covering. — Name and trace through the different invertebrate 

 branches all means of covering the body; state wjiat it is called and its uses 

 to the animal and to man. 



11. Color. — Trace the purpose of color or color patterns. P'ind examples 

 of warning colors, alluring colors, terrifying colors, of colors for protective 

 resemblance. What gives color to an animal? 



12. Parasites. — Trace parasitism through the invertebrates. Causes? 

 Results of parasitism on the parasite and upon the host? 



13. In the threefold struggle for existence, which fold is the most ap- 

 parent for the invertebrates? Why? 



14. Of the five great environmental factors, which one is the most ap- 

 parent in the existence of the invertebrates? 



15. Heredity. — In what ways do you see or infer that heredity holds the 

 invertebrates? i. e., Why do they remain invertebrates? 



16. Recognition. — Find examples of recognition of its own or different 

 species by color, sound, odor, or shape. 



17. Terrifying appearance, attitude, or sound. Find invertebrate ex- 

 amples of each. 



18. Relations with Other Animals. — Find examples of: (1) solitary inver- 

 tebrates; (2) gregarious ones; (3) social ones; (4) commensalism; (5) sym- 

 biosis. 



19. Multiplication. — Find examples of: (1) asexual invertebrates; (2) 

 hermaphroditic ones; (3) dimorphic, trimorphic, and polymorphic ones; 



(4) parthenogenetic ones; (5) of branches that afford examples of both 

 asexual and sexual ones. 



20. Show that its object is variation rather than reproduction, as there 

 was reproduction long before sex existed. 



21. Dispersal. — Name direct, as well as indirect, means of invertebrate 

 dispersal. 



22. Barriers. — Show that large rivers, oceans, etc., are barriers to in- 

 vertebrates. 



.23. Animal Behavior. — See "Animal Behavior," Laboratory Guide, i)p. 

 12-16. 



24. Irritability. — Trace irritability of the protoplasm from Ameba. 

 Will it develop into the nervous system and special senses of the higher 

 invertebrates? If not, where do the nervous system and special senses 

 originate? 



25. Contractility. — Will protoplasmic contractility develop into the mus- 

 cular system, and locomotion? 



