398. QUESTIONS, PROBLEMS, AND SUGGESTIONS 



,4) The Nervous System and Special Senses — the co-ordinating appa- 

 ratus for the body systems and the mind, or animal behavior. 



. f (5) The Digestive System — the means of absorption from food. 

 .2 (6) The Circulatory System — the means of blood nutrition of tissues. 

 •"H ] (7) The Respiratory System — the means of oxygen nutrition of tissues. 

 ^ (8) The Excretory System — the means of waste elimination of body. 

 [ (9) The Reproductive System — the race repair system. Note the 

 function of each of the nine body systems enumerated in worms or other 

 of the higher forms. 



17. Is the worm-body a typical, characteristic animal body? If not, 

 what animal would you designate as a typical, characteristic, complete, 

 perfect animal body? 



18. Are insect-bodies, fish-bodies, bird-bodies, mammal-bodies an im- 

 provement over the worm-body model? If so, in what respects? 



19. Degeneration. — How does an animal body begin to degenerate? 

 What organ or system first weakens and how does this affect other organs 

 or systems? How does degeneration of the body affect the mind or be- 

 havior? Give examples of degenerate worms. 



20. Increasing Complexity. — How does an animal body advance and be- 

 come more complex? How does the animal mind or animal behavior in- 

 crease in complexity? How degenerate? Why? 



ECHINODERMATA 



1. Bodij Plan. — Symmetry of the larval body? Of the adult body? 

 Metamorphosis of the body? (p. 56). 



2. Living forms of this branch solitary or gregarious? Fixed or free? 

 Marine or freshwater habitat? 



3. Skeleton and Covering. — Of what do they consist? 



4. Name means and manner of nutrition, reproduction, locomotion, 

 dispersal, and defense. 



5. Water-vascidar System. — Its structure and function? Is it found in 

 any other branch? (p. 54). Why this specialization for this branch? 



6. Nervous System and Special Senses. — Of what do they consist in this 

 branch? 



7. Animal Behavior in this branch as compared with that of other 

 branches just studied? Any advance or degeneration? 



8. The echinoderms are a singularly isolated group (p. 64). How would 

 you account for this? What is the effect of isolation on a group of animals 

 or on a single species? What is the peculiarity of the hermit? Why so? 



9. Economics. — Name echinoderms of commercial, or scientific use or 

 harm to man (p. 55). 



10. Hypothetic Case. — If you could do so, what changes would you make 



