I04 LABORATORY GUIDE IN BACTERIOLOGY 



3. Special study B. — Observe the lesions in a 

 guinea-pig or rabbit dead of tuberculosis, which has 

 been inoculated about four weeks previously. Note the 

 caseous matter at the site of the inoculation, the enlarged 

 yellowish inguinal and axillary glands, the small gray 

 or yellowish tubercles in the liver, lung, spleen, mesentery, 

 etc. Stain for bacilli from such sites. Make cultures on 

 glycerin-agar or dog-serum (see the textbook). 



4. Special study C. — Stain Moeller's grass bacillus 

 from agar-culture by the same method, omitting the 

 counters tain. 



5. Special study D. — 



a) Grind in a mortar, previously sterilized, a small 

 amount of a culture of the grass bacillus, and mix with 

 some sterile milk. 



b) Make a cover-slip preparation of this mixture, and 

 stain for tubercle bacilli. At what conclusions as to the 

 quality of the milk would you arrive, if you should find 

 acid-resisting bacilh in a fresh sample of milk? 



