64 AIDS TO BACTERIOLOGY 



the same year, and they arranged human tubercle bacilli 

 in two classes those growing with difficulty on certain 

 artificial media, which they called dysgonic, and those 

 growing readily on the same media, which they called 

 eugonic. Experiments with dysgonic bacilli of human 

 origin gave results identical with those made with bovine 

 bacilli. In a few cases both the human and bovine types 

 may be found together. As a rule, pulmonary lesions in 

 man are due to the human type of bacillus, but sometimes 

 the bovine tubercle bacillus is solely responsible. (Kossel 

 found two cases in 709 cases of phthisis.) See p. 265. 



The majority of cases in which the bovine tubercle 

 bacillus produces lesions in man are cases of alimentary 

 tuberculosis: cervical gland and primary abdominal 

 tuberculosis. In the latter class of cases at least the 

 tubercle bacillus has unquestionably been swallowed. 

 The Commissioners stated their conviction that a certain 

 number of cases occurring in the human subject, especially 

 in children, are caused through the introduction into the 

 body of bovine bacilli, the majority of cases being caused 

 through tuberculous milk. 



As long ago as 1886,* Harries stated from clinical 

 observations that lupus was not due to tubercle bacilli 

 as then known to infect human beings, and a few years 

 ago the opinion that lupus was an infection with the 

 bovine type of tubercle bacillus gained credence. Nine 

 out of the twenty cases of lupus investigated by the 

 Commission proved on culture to be bovine tubercle 

 bacilli, though generally they were of feeble virulence. 

 Park and Krumwiede found that from 6 to 10 per cent, 

 of all deaths due to so-called surgical tuberculosis were 

 caused by bovine tubercle bacilli, the cases of tuberculous 

 adenitis and abdominal tuberculosis of children being 

 more often caused by the bovine than by the human type. 

 The same was found true, though to a less extent, in 

 adults. Stiles says that 90 per cent, of surgical tuber- 

 culosis seen in Edinburgh was due to bovine tuberculosis 

 and 90 per cent, of the gland cases were due to infection 

 through the tonsils by milk. Some cases of tuberculous 

 joints which show no improvement under human tuberculin 

 treatment rapidly undergo cure with bovine tuberculin. 



* ' Lectures on Lupus ' : A, Harries, M.D., and C. Campbell, 

 M.D. Bailliere, Tiudall and Cox. 1886. 



