THE STUDY OF BACTERIA 125 



EXERCISE 43. THE STUDY OF BACTERIA 



Studies will be made of ten bacteria representing the 

 different morphological types. These are to be identified 

 by morphological and cultural characteristics. 



Pure cultures of these organisms will be found on each 

 desk in the tumblers marked " Laboratory cultures." 

 Always return laboratory cultures to these tumblers imme- 

 diately after using. 



DANGER. Some of these organisms are pathogenic. 

 If you do not handle them with care and according to 

 directions you endanger not only yourself, but all working 

 in the laboratory. Do not be careless. Handle all organ- 

 isms as if they were pathogenic. This is a good habit; get 

 it immediately. (See " Care of Cultures," pp. 46-48) The 

 instructor will designate which organisms are pathogenic. 



Apparatus. Clean cover-glasses; clean concave slides; 

 clean plain slides; ten agar slants; ten tubes sterile agar 

 for plates; ten tubes nutrient broth; ten tubes nutrient 

 gelatin; ten tubes litmus milk; ten tubes glycerin potato; 

 ten tubes Dunham's solution; ten tubes nitrate peptone 

 solution; four fermentation tubes of plain broth; four 

 fermentation tubes of dextrose broth; four fermentation 

 tubes of lactose broth; four fermentation tubes of sac- 

 charose broth; centimeter scale; gasometer; lead acetate 



DESCRIPTION OF PLATE V 



I. 1, Bad. tuberculosis; 2, B. typhosus; 3, Bad. leprce; 4, Bad. 

 anthracis (strepto-bacterium, two with spores); 5, Bad. diph- 

 therias (club-shaped); 6, anthrax spore, germinating (polar); 

 7, B. amylobader (clostridium) ; 8, Streptococcus pneumonice 

 (diplococcus with capsule). 



II. 1, B. subtilis (strepto-bacillus, peritrichous flagella, one with 

 spore); 2, B. subtilis (peritrichous flagella); 3, formation of a 

 new filament from a germinating spore; 4, spore of B. subtilis; 

 5, germinating spore of B. subtilis (equatorial); 6, beginning 

 germination. 



