46 



GENERAL BACTERIOLOGY 



d. With the loop place a drop of liquid agar so as to cover up 

 streak. 



e. Flame a hollow-ground slide and seal the cover glass to it. In- 

 cubate and later examine and sketch. 



REFERENCES. Hill, Hanging Block, Jour. Med. Research, 1902, 

 2; 202. 



EXEECISE 24. STUDY OF INVOLUTION FORMS. 



a. Grow Bacillus subtilis (EHRENB.) MIG. in bouillon, and also 

 in water containing 0.1% asparagin, 10% sugar, and by means 

 of stained cover-glass preparations compare the individual organ- 

 isms in each case in regard to their form and size. The degenerated 

 or involution forms are more apparent by staining. Draw several 

 cells illustrating a variety of involution forms. 



~b. Examine a culture of Bacterium diphtheriae (LOEFFLER) MIG. 

 on Loeffler's blood serum. Read M. & R. 5. 



EXERCISE 25. STUDY OF ENDOSPORES. 



a. Make cultures on peptoneless agar, or on an agar tube to which 

 a few drops of calcium hydrate have been added, of the following 

 organisms and incubate at 28 or 38 C. : 



Bacillus subtilis (EHRENB.) COHN. 



Bacterium anthracis (Kocn) MIG. (or Bacillus mycoides 

 FLUEGGE). 



Bacillus amylobacter VAN TIEGHEM (or any clostridium form). 



Bacillus tetani NICOLAIER (or any "drumstick" bacillus). 



ft. When the cultures are 48 hours old mount films without stain- 

 ing, examine and fill out following table : 



