LIVING BODIES AND CELLS 21 



Notice the flat scales of irregular shape. Each scale is a separate 

 living cell. It is nearly transparent, but its nucleus appears as a 

 slightly darker spot. Make a drawing of the cells. 



Examine cells scraped from the skin upon the back of the hand; 

 and cells scraped from the pulp of a leaf. Examine a bit of the green 

 scum, called pond alga, which forms upon stones in fresh-water ponds. 

 Notice the long cells joined end to end and containing green matter. 



2. Take a drop of stagnant slimy water from a rain barrel or from a 

 kitchen drain or from a stagnant pool. Examine it with a power of at 

 least 100 diameters. A specimen of the ameba is likely to be found 

 rolling about. Notice its nucleus, and also dark spots in its body which 

 are probably food which it has swallowed. Make a sketch of an ameba. 



REVIEW TOPICS 



1. Define Anatomy. 



2. Define Physiology. 



3. Define Hygiene. 



4. Describe an ameba. 



5. Describe a cell. 



6. Describe connective tissue. 



7. Give the three tests by which a cell or other body is 



known to be alive. 



8. Give other distinctions between living and lifeless 



bodies. 



9. Give the relation of the mind to the cells of the body. 



10. Define a t is site and name the different tissues of the 



body. 



1 1 . Show that the blood is a tissue. 



12. Give the different J?#fc& in the body. 



13. Define an organ. 



14. Define a system. 



15. Describe the instrument by means of which the dif- 



ferent cells and tissues of the body are studied. 



