238 c(elentp:rata 



maries. Sometimes, by careful work with the mi- 

 croscope, the sperm cells may be made out in the 

 spermary, or breaking through into the water. 

 (2) Look for buds. In what different stages do you find 

 them? Sketch. 



6. The Skin or Dermal System in the higher forms. The 

 skin is an organ of respiration and excretion. 



(1) Does this animal possess a skin? If so, of what use 



is it to the animal? 



(2) Are there any growths of the skin? (if it has a skin), 



such as cilia, scales, feathers, hair, etc. 



7. The Nervous System. 



(1) Of what does it consist in this animal? 



(2) Use to the animal? 



(3) What special senses have you observed this animal use? 



(4) Prove that it has a sense of touch. 



(5) Prove that it has either smell or taste. 



8. Organs of Defense or Offense. Look for tiny swellings of 

 the ectoderm, especially of the tentacles. These are the nema- 

 tocysts or stinging cells. Place a drop of acetic acid under the 

 cover-slip and watch these cells. What takes place? 



SYSTEMATIC STUDY 



1. Body segmented or unsegmented? 



2. Symmetry? 



3. Plan of structure of body and appendages of this animal? 



4. MultipHcation? 



5. Means of defense? 



6. The Coelenterate belongs to Branch Coelenterata, for it 

 has the following branch characteristics common to sea-anem- 

 one, hydra, coral, polyps, and jelly-fish: (Student fill blanks 

 1-5.) 



(1) As to body, 



(2) As to appendages, 



(3) As to plan of structure, 



(4) Multiplication, by 



(5) Defense, by means of 



7. Remark. — The object of this systematic study is to dis- 

 cover the Coelenterate Branch Characteristics. 



