BACILLUS TUBERCULOSIS AND ALLIED ORGANISMS 113 



" higher bacteria," mycobacteria, similar to actinomyces. 

 Other acid-fast bacilli exhibit similar types, and it is possi- 

 ble that the bacillary parasitic form is only one stage in the 

 life-history of the organism. 



Little granules, arranged like streptococci, which take the 

 characteristic stain, and look as if the protoplasm had been 

 destroyed that inclosed them, are frequently found in sputum. 

 Some believe these " splinters" to develop into regular bacilli 

 in cultures. 



Fig. 49. Tubercle bacillus in sputum (Frank el and Pfeiffer). 



Bovine tubercle bacilli are about one-third smaller than hu- 

 man tubercle bacilli. 



Resistance. Bacilli in sputum, in dark, cool places may live 

 several months. Dried sputum in sunlight and dust is infec- 

 tive not more than ten days. The bacilli will resist in the dry 

 state a temperature of 100 C. one hour. In moisture death 

 occurs at 60 C. in a few minutes. 



Chemic Properties. A waxy substance found in pure cul- 

 tures, due to fatty acids. The fat-free substance is nucleo- 

 8 



