EXERCISE 80 



Protoplasm in plant and animal cells is constantly producing substances that are of no further use 

 to it, or separating useless substances out of the material received. Some of these are passed out of the 

 cells and out of the organism ; others are passed out of the cells but gathered up in parts of the organism 

 where they cannot injure the living parts. 



Problem. What is the character of some of these waste substances ? 



What to use. Petals of pansy ; stem of horsetail, or scouring rush (Equisetuni) ; Indian turnip 

 (Ariscemc?) ; microscope ; slides ; cover glasses. 



What to do. Mount piece of pansy petal, of scouring rush, and of Indian turnip on slides anc 

 examine with the microscope. Note colored fluids and colored particles in the pansy ; crystals of silica 

 in the horsetail ; crystals of lime oxalate in the Indian turnip. Place a tiny bit of the Indian turnip or 

 the tip of your tongue and note sensation. 



Record. Make clear diagrams showing each kind of body found in your study ; label structure shown 



NOTE. The peculiar taste of the Indian turnip is due to the action of the fine crystals shown in some of the cells 

 these crystals are called raphides (three syllables). 



Questions. 1. What substances are formed in living cells that are not injurious to protoplasm? 



2. Name some substances that are stored up in cells and are of use to the organism. 



3. How can you tell whether a given substance produced in a cell is a waste product? 



4. What substances produced by protoplasm are not solids ? 



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