PROBLEM I . The Co7n position of Living Things 



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Fig. 146 The lenses below 

 the stage are not usually at- 

 tached to high school micro- 

 scopes. When you look 

 through the microscope you 

 7ise two sets of lenses. Each 

 set consists of two or more 

 separate lenses. Can you find 

 the sets? This jnicroscope 

 is cut through the middle. 



(BAUSCH & LOMB OPTICAL CO.) 



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1 1. 



In review state briefly what you have learned in this problem about: 

 {a) Cells, explaining the diflferences between plant and animal cells. 

 (b) Protoplasm, its characteristics and the elements of which it is 

 composed, {c) The compounds which are mixed together in living 

 matter, {d) Why plants and animals are said to be fundamentally alike. 



Exercises 



1. If you will have an opportunity to use a school microscope you 

 should be familiar with its parts. Starting at the bottom they are: base; 

 mirror; diaphragm (attached to the bottom of the stage); stage (which 

 holds the glass slide); arm (the part by which you carry the microscope); 

 barrel (the thick vertical tube); 7wsepiece (revolving part at the bottom 

 of the barrel); objectives (two or more lenses screwed into the nosepiece); 

 coarse adjiistDiem (two large wheels on either side of the barrel); fine 

 adjiistviejU (two smaller wheels); ocidar or eyepiece (the lens fitted into 

 the top of the barrel). 



