16 GENERAL BACTERIOLOGY LESSON in 



(e) Place the cover-glass drop downwards over the central 

 perforation of the moistened filter-paper. 



Examine the drop with a high power, using a narrow 

 diaphragm. 



Focus for the margin of the drop, and then move the 

 specimen till a bacillus appears in the field. 



Now place a drop of oil on the cover-glass, and examine 

 with a -^ in. oil immersion. 



Distinguish between true and Brownian movements. 



