74 LABORATORY BACTERIOLOGY 
EXERCISE XXIV Z 
BACTERIUM ANTHRACIS (continued) 
111. Work for this exercise. Reéxamine all of the cultures 
of Bact. anthracts and describe any changes in their appearance 
which may have taken place. 
Stain a few cover-glass preparations according to Gram (§ 40). 
Examine the agar culture for spores in a hanging-drop prep- 
aration and in a stained cover-glass preparation. Describe 
the appearance of the bacteria and spores in each. 
Study and describe the appearance of the colonies on the 
agar plates. Make an outline drawing of a few of the surface 
and deep colonies. 
Reject all cultures except the agar plates, which may be 
kept until the next exercise for further observation before 
rejecting. (These cultures should be put in charge of the 
instructor, who will see that the spores are destroyed before 
the tubes are cleaned.) 
Inoculate-a tube of Loeffler’s blood serum and glycerin agar 
with Bact. diphtherie from a culture furnished, for study at the 
next exercise. 
