38 THE NATURE AND NEEDS OF LIVING MATTER 



preparations under high power, and permit the pupils, one 

 at a time, to briefly note the protoplasmic movements. 



Since elodea is quite common in ponds and streams, and is 

 so easily kept on hand in aquaria, it is recommended as best 

 for the present purposes. 



Observations. 1. Examine a bit of mounted living leaf of 

 elodea or other selected study! What is the general color ? 

 Can you see cell walls ? 



2. Are the cells single, or joined in a tissue ? 



3. Look closely for any indications of movements in the 

 cell moving protoplasm. What is its appearance? 



4. Does the protoplasm (cytoplasm) move in any special 

 ways with reference to the nucleus ? 



Conclusions. 1. In what part of plants may protoplasm be 

 found ? 



2. Write a paragraph, telling of the appearance, movements, 

 etc., of protoplasm. 



Questions 



1. What is a cell ? Tissue ? Organ ? 



2. What is an organism ? Give reasons for your answer. 



3. What is protoplasm ? Cytoplasm? Nucleus? 



4. What is the unit of structure of living things ? 



5. What are some of the properties of living things ? 



6. How may cells reproduce ? 



7. What do you suppose is meant by the statement "one 

 touch of nature makes the whole world kin " ? 



8. Why is it necessary that there should be differences of 

 function among the cells of a body ? 



9. Why could not a cell in the body provide for its own 

 wants ? 



10. What happens to a body if part of the cells fail in their 

 work? 



11. Mention some points in which the body reminds you of 

 a community of people. 



12. What are some of the needs of a cell ? 



