4 GENERAL BIOLOGY. . 



7. The tube of the microscope should always 



slide smoothly. If it does not, take it 

 out, wipe it clean, and apply a little vase- 

 line. 



8. When lifting the microscope, do not take 



hold of the column above the stage, as 

 this is apt to disarrange the fine adjust- 

 ment. 



9. When not in use, the microscope should Tse 



put into its box (observe paragraph 8). 

 Each objective should be put into its own 

 brass box with the lid that corresponds 

 (otherwise the thread of the screw may 

 be injured, and the boxes cannot be 

 tightly closed, to keep out moisture, etc.). 



II. ON DRAWING. 



Everything of importance should be recorded by 

 sketches or diagrams and by notes. Try to show 

 in the sketches as clearly and accurately as possible 

 the essential features of what has been seen, and 

 add concise explanations. In order to show the 

 natural relations of the parts it may be necessary 

 to combine several views of the object. 



Draw on a large scale ; the sketches cannot be 

 too large. 



It is best to draw to scale, i.e., either the exact 

 size or half or double, etc., the size of the object. 



Name the parts represented in the drawing, and 



