356 BACTERIOLOGY. 



when subsequently treated with acid alcohol (nitric 

 acid, 1 part ; alcohol, 10 parts). By similar treatment 

 for the same length of time bacillus tuberculosis does 

 not ordinarily become stained. 



These points, particularly what has been said with ref- 

 erence to the smegma bacillus, are of much practical 

 importance, and should always be borne in mind in con- 

 nection with the microscopic examination of materials 

 to which these organisms are likely to gain access. It 

 is hardly necessary to say that in the examination of 

 sputum and pathological fluids from other parts of the 

 body the tubercle bacillus is, of the organisms noted, 

 always the one most commonly encountered, while the 

 organism described by Lustgarten as the bacillus of 

 syphilis is seen so rarely that many trustworthy investi- 

 gators question its existence as a species distinct from 

 the ordinary smegma bacillus. 



From time to time fowls are known to suffer from 

 a form of tuberculosis that in a number of ways sug- 

 gests human or mammalian tuberculosis. The bacillus 

 causing the disease, the so-called bacillus of fowl tuber- 

 culosis, bacillus tuberculosis avium, while simulating the 

 genuine bacillus tuberculosis morphologically, differs 

 from it both in cultural and pathogenic peculiarities. 

 Thus, for instance, it develops into much longer and 

 somewhat thinner threads; grows rapidly on media 

 without glycerin or glucose ; does not grow on potato ; 

 develops as well at from 42° to 43° C. as at 37° to 38° 

 C. ;' its virulence is not diminished by cultivation at 

 43° C. ; development on artificial media begins in from 

 six to eight days after inoculation ; young cultures on 



1 The normal body.temperature of fowls rouges between 4.15° and 

 42.5° C. 



