420 ACTINOMYCETES. 



can be infected. The course is very chronic; giant cells 

 are rare; bacilli are present in great abundance. 



Immunity against avian tuberculosis exists in the dog, 

 monkey, and guinea-pig; but the last-named animal after 

 injection dies with a slow marasmus (chronic intoxication). 

 Rabbits are rarely susceptible. 



Leray (H. R., 1896, 358) describes differences in the 

 pathologico-anatomic picture in rabbits which are inocu- 

 lated with avian and mammalian tuberculosis. In the 

 former caseation is lacking, but there are many giant 

 cells, with common inclusions of the organisms; in mam- 

 malian tuberculosis the reverse obtains, the caseation 

 being extensive, giant cells few, the T. B. usually free. 



Mycobacterium tuberculosis var. y piscicola. L. and N. 



(Plate 62, v-ix.) 



Literature. — Bataillon, Dubard, and Terre (C. B. XXII, 61); Krai 

 and Dubard (Rev. de la tuberc., 1898, No. 2). 



The French authors cultivated the organism, which re- 

 sembles the T. B. , from a tumor of carp about the size of 

 a pigeon's egg. It is not motile, is acid proof, forms 

 branches, and grows at 23°-25° as the optimum tempera- 

 ture (minimum, 12°). In bouillon there are abundant 

 flocculi, which settle to the bottom; upon potato there 

 occurs a thin whitish growth; gelatin is not liquefied. 



In order to prove that their organism is the T. B., 

 acclimated to cold-blooded animals, fish and frogs were 

 inoculated and fed with cultures of human and avian 

 tuberculosis. From the organs of such fish the var. pisci- 

 cola was in fact obtained. 



In association with Dr. Kumulis we have thoroughly 

 studied a culture obtained from Krai, and have completely 

 confirmed the statements of the French investigators. 

 Growth stops at once at 37°, and at 20°-25° it is a little 

 more luxuriant than that of the ordinary T. B. in the in- 

 cubator. In the microscopic examination we saw no 

 branching, probably by chance. In gelatin plates (62, vi) 

 there occurs a rather tough, dry, whitish-yellow, wrinkled 

 growth, which upon being magnified sixty times corre- 

 sponds to the T. B. upon glycerin-agar (62, vn). In the 



