STRUCTURE AND FUNCTION 59 



3. Is there a skeleton ? If so, describe it. What ap- 

 pears to be its use ? In corals, notice the radiating parti- 

 tions. 



4. Has the specimen any nettle cells .■• If so, where are 

 they located ? 



5. Are all the polyps of the colony alike .' If not, how 

 many kinds are there ? How do they differ ? 



What is each kind best fitted to do? What is the probable result of 

 this differentiation? 



6. What kinds of reproduction, if any, does the speci- 

 men you are studying show ? 



Find out from books what other forms of reproduction are sometimes 

 used by this animal. 



Suggested drawings, 

 a. At least one drawing of each ccelenterate you study. 



Summary of the Comparative Study of Coelenterates 



1. How may polyps in colonial forms differ from polyps 

 which live singly .-' 



2. What variations in methods of reproduction are shown 

 in this group } 



3. Which of the polyps you have studied shows the 

 greatest differentiation ? In what ways } 



4. What characteristic do you find common to all the 

 coelenterates you have studied .? 



Review and Library Exercise on Coelenterates 



1. What are the characteristics which distinguish 

 coelenterates ? 



2. Give the classes of coelenterates, with the character- 

 istics and an example of each. 



