[1] 67 BACTERIA 



A . Bacteria in pea extract. Mount a drop of the turbid liquid (pea infusion that has been exposed to 

 air for a fortnight), put on a coverslip and observe the numerous bacteria in motion. The preparation must be 

 very carefully focussed with the high power. 



B. Bacteria in air. Remove the cover from the dish of sterilised gelatine provided, thus allowing the 

 dust of the air to settle on it. Replace the cover after an hour and label the dish with your name. After a week 

 or two the number of bacterial and fungal colonies arising from the bacterial and fungal spores deposited from 

 the air can be counted. 



C. Bacillus subtilis. Examine the stained preparation provided. Notice and draw the abundant rod- 

 shaped bacteria. Compare their size with that of a yeast cell. 



D. Examine the stained slides of various pathogenic (disease) bacteria shewing different bacterial forms, 

 spore formation, etc. 



