THE TUBERCLE BACILLUS 615 



acteristic of the avian type that cultures on liquid media (glycerin 

 broth) grow as readily within the liquid as on the surface and may 

 even become homogeneous. 



Guinea-pigs, very susceptible to human tuberculosis, are very 

 refractory to infection with the avian type; while, on the other hand, 

 rabbits which are resistant to the human type, succumb rapidly to 

 infection with avian tuberculosis. 81 Prolonged cultivation and passage 

 through the mammalian body is said to cause these bacilli to approach 

 more or less closely to the mammalian type. Conversely, Nocard 82 

 claims to have succeeded in rendering mammalian tubercle bacilli 

 pathogenic for fowl by keeping them in the peritoneal cavities of hens 

 in celloidin sacs for six months. 



Recently Koch and Rabinovitsch 83 have isolated from the spleen of 

 a young man dead of tuberculosis, a microorganism which, culturally, 

 morphologically, and in its pathogenic action upon birds, seemed to 

 belong to the avian type. Lowenstein 84 describes a similar organism 

 cultivated from a human case which seems to be a transitional type. 

 Observations of this order ar^, however, too few at the present time to 

 be used as the basis of a definite opinion as to the relationship between 

 the two varieties. 



Tuberculosis in Cold-blooded Animals. The bacillus isolated by 

 Dubarre and Terre 85 resembles Bacillus tuberculosis in morphology and 

 in a certain degree of acid-fastness. It grows at low temperatures, 

 15 to 30 C. It is non-pathogenic for animals, but kills frogs within a 

 month. Except for the acid-fastness it has little in common with 

 Bacillus tuberculosis. 



Similar acid-fast bacilli have been isolated from other cold-blooded 

 animals (carp, frogs, turtles, snakes) by many observers. 



There have been many attempts to show a close relationship between 

 the tubercle bacilli of cold-blooded and those of warm-blooded animals. 

 Moeller, Hansemann, Friedmann, Weber, Ktister, and others have 

 given this subject particular attention and it has gained especial interest 

 because of the recent notorious claims of Friedmann that he had suc- 

 ceeded in obtaining, from turtles, a strain of acid-fast bacilli which could 



et Gamalcw, Arch. do nu''d. expor., 1891; Courmont et Dor, Arch, de 

 mod. oxp., 1S91. 



l, Ann. de 1'inst. Pasteur, 1S9X. 



mid Ktiltiiiovitxi'h. Viirh. Arch., Beihoft to Bd. 190, 1907. 

 n *Lowenstein f quoted from Koch and Kabinovitsch, loe. cit. 

 M Di/tbarire et Tcrre, Conipt. rend, de la soc. de biol., 1897. 



