TUBERCULOSIS 45 



than that shown by this animal to either the human or bovine variety. 

 Rabbits seem to be more susceptible, though typical tubercular nodules 

 are not always developed in these animals, many dying from septi- 

 cemia. Calves fed on the avian bacillus may develop local tubercu- 

 losis in the intestine and mesenteric glands, but this seems to have little 

 effect on the growth and health of the animal. Subcutaneous injec- 

 tions in cattle cause an inflammatory reaction which may extend to 

 neighboring glands, but fail to develop general tuberculosis. In the 

 studies of the varieties of tubercle bacilli found in man, already 

 referred to, three cases of infection with avian bacilli were found. 

 However, it is not certain that these people were not also infected 

 with one of the other varieties. In at least three other cases the avian 

 bacillus has been found. 



That the flesh of tuberculous fowls frequently comes to the table 

 is beyond dispute. The methods of cooking probably kill all the bacilli. 

 Besides, the appearance of the liver is so striking that this organ is 

 removed before dressed fowl comes under the eye of the consumer. 

 No observant cook could overlook so abnormal an organ as the liver 

 in a well-developed case of tuberculosis gallinaceus. 



The Piscidian Variety. Fish, amphibians and reptiles are suscep- 

 tible to a form of tuberculosis due to a variety of the bacillus which 

 is not capable of growth at the temperature of the body in mammalians 

 and, therefore, cannot be a source of infection in man. One would not 

 knowingly eat a tuberculous fish, but if he unknowingly does so, 

 tuberculosis will not result. 



Other Acid-Fast Bacilli. There are several well-known and thor- 

 oughly studied saprophytic bacteria which have a close resemblance 

 to tubercle bacilli in their reactions towards certain stains. They are 

 not easily stained by ordinary dyes, but when thoroughly stained with 

 carbol-fuchsin or similar agents the color is not removed by washing 

 with dilute mineral acid. These organisms are classed with tubercle 

 bacilli as "acid-fast" organisms. These have been especially studied 

 by Moeller who has defined several species or varieties. One point of 

 interest is that they may be mistaken for tubercle bacilli. This is likely 

 to occur because one of them is found on timothy hay and is known as 

 "Moeller's timothy" bacillus and another is found in cow dung. So 

 far as they have been tested they are not pathogenic to any animal. 



