CGELENTERATA 



MORPHOPHYSIOLOGIC STUDY 



Suggestion. — This study may be adapted for the study of 

 any Coelenterate by omitting some questions and enlarging upon 

 others. The Hydra is probably the most easily obtained, and 

 makes a good study of this branch. 



CoUect from quiet streams or ponds, duck-weed or other water 

 plants. Place them in a large glass jar and put the jar where the 

 light will shine upon it. The hydras will collect on the hghted 

 side, as they are positively heliotropic. 



Break off a tiny piece of stem or leaf supporting a hydra. 

 Place it upon a slide with a little water and watch it for several 

 minutes. Does it change its position? When it is extended, 

 touch it with a needle. What does it do? 



1. The Body. 



(1) Is it one celled or many celled? 



(2) Size. How long is your specimen? (Length in inches 



or fraction of an inch.) 



(3) Shape. Is it tubular, or what shape is it? Broad or 



slender? 



(4) Is the body fixed or free? If fixed, by what portion of 



the body? How? Is it temporarily or permanently 

 attached? Carefully push it loose with the handle 

 of your scalpel. What does it do? 



(5) Closed or open? If the body is open, describe its 



opening and give its position on the body. (Use 

 the hand lens for this, or, if necessary, place your 

 specimen on a slide in a drop of water, put a thread 

 or tiny broom straw on each side of the hydra, and 

 cover it with a cover-slip, resting the edges of the 

 cover upon the threads or straws to avoid injuring 

 the specimen, and continue your study under the low 

 power of the microscope.) 



(6) Color. What is the color of your specimen? Is it 



of uniform color on all parts of the body? 



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