EXPERIMENTS WITH PURE CULTURES 145 



morning and evening over a long period being ioi"2° F. 

 and io2*2° F. respectively. Repeated examination of 

 the faeces failed to reveal any acid-fast micro-organism 

 resembling Johne's bacillus. On June 5, 191 1, the cow- 

 calved. Parturition was normal and the calf quite 

 healthy. 



On October 23, 191 1, she was killed, and a post- 

 mortem examination made. The carcass showed 

 marked emaciation, with practically complete absence 

 of subcutaneous and intra-abdominal fat. The bronchial 

 glands showed advanced tubercular lesions, while the 

 pleura and the thoracic surface of the diaphragm 

 showed a few recent tubercular patches. A few 

 tubercular nodules were also present in the lungs. 

 Some of the intestinal lymphatic glands also showed 

 tubercular lesions of recent origin. All the remaining 

 organs and tissues of the body, with the exception of 

 the intestines, appeared normal. When the intestines 

 were opened, a considerable thickening of the mucous 

 membrane was observed. This was most marked in 

 the vicinity of the ileo-caecal valve, the terminal portion 

 of the ileum, and the first part of the large intestine. 

 No ulceration or caseation of the mucosa was present. 

 The general thickening and corrugation of the mucosa 

 presented the characteristic appearance of Johne's 

 disease, and films made from beneath the mucous 

 membrane showed a few small acid-fast bacilli. From 

 the tubercular bronchial gland we obtained a pure 

 culture of a bovine strain of tubercle bacillus ; but all 

 the cultures taken from the intestinal mucosa on to 

 the special media remained sterile. It is unfortunate 

 that the specific bacillus was not isolated from this 

 case. Nevertheless, from the naked-eye appearance, 

 and still more from the histological examination of the 

 intestine, there is no doubt that this animal had con- 



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