Pathogenic Action of Bovine Bacilli. 623 



the virulence of a given strain in its first generation l\y its cultural 

 characteristics alone. In its summary the report of the commission lays 

 stress upon the fact that the bacillus of Group I differs from that 

 of Group II not only in its lesser degree of virulence, but also in 

 its manner of growth and that, in view of this two-fold difference 

 it seems impossible to believe that human tuberculosis (II) is one and 

 the same disease as bovine tuberculosis (I). Finally, the practical 

 conclusion is expressed that a certain number of cases of tuberculosis 

 of man and especially of children is the direct result of infection by 

 the bacillus of bovine tuberculosis. 



Of other investigations made along these lines the following may also be 

 mentioned. 



Hamilton repeated the experiments of Koch & Sehuetz, nsing the same num- 

 ber of cattle and was able to demonstrate tuberculous lesions in 1.5 animals infected 

 with human material. Dammann & Muessemeier did not succeed in making calves 

 very sick by feeding sputum and pure cultures of human bacilli but they succeeded 

 in producing progressive, though in most cases only slight tuberculosis in 1.3 

 calves by the subcutaneous administration of S cultures out of a total of 18 pre- 

 pared from every possible affected organ. One strain killed a calf in 28 days 

 and another, after intravenous injection, in 17 days. These authors could not 

 recognize two distinct and separal)le types with transition forms of bacilli and 

 believe rather that the different strains are merely varieties of the same species 

 that have adapted themselves to conditions existing in the bodies of each species of 

 animal. 



Fibiger & Jensen investigated seven cases of unequivocal primary tulier- 

 culosis of the alim.entary canal of children from 4 months to 12 years of ago. They 

 found five cases in which the bacilli possessed a very pronounced virulence for 

 cattle (in three cases the children in question had for some time consumed raw 

 milk from uninspected dairies). Other authors (Schweinitz & Schroeder, Westen- 

 hoeflfer, Lignieres, Schweinitz, Mohler, Eabinowitsch) also have found bacilli from 

 tuberculous children (especially from primary intestinal tuberculosis) highly 

 virulent for cattle. Thus Mohler & Washburn examined twelve strains from man, 

 one from monkeys, four from cattle, two from dogs and one from sheep and 

 found that bacilli virulent for cattle may and do occur in human beings. They 

 were of the opinion, however, that two tj^ies could be recognized although there 

 were intermediate transition forms and that the individual types were not neces- 

 sarily confined to definite species of animals. Finally, Behring maintains that 

 there are human strains of tubercle bacilli that are more virulent than material 

 obtained directly from cattle and Dorset, also, found many strains of bacilli of 

 human tuberculosis that were just as virulent as those of bovine tuberculosis. 



Eber tested the virulence of the bacilli in seven cases of intestinal tuber- 

 culosis of chihlren and found only two cases in which they were only slightly or 

 not at all virulent, two cases in which the virulence was of average intensity and 

 three cases in which the bacilli were highly virulent for cattle. In later investiga- 

 tions only two out of 8 cases of human tuberculosis proved non-virulent for cattle 

 while repeated attempts with the remaining 6 strains were uniformly successful in 

 producing serious and in some cases fatal tuberculosis in cattle (especially after 

 combined subcutaneous and intraperitoneal administration of the virus). Two 

 strains exhibited only a medium degree of virulence for cattle but after being 

 transferred to another animal they became highly virulent. Since both strains 

 showed atypical characteristics from a morphological point of view also, as well 

 as in their action on rabbits, Eber is inclined to look upon them as transition 

 forms which seem to constitute a connecting link between the two extreme types 

 and make the gradual transition from one form to the other seem possible. 



Pathogenic Action of Bovine Tubercle Bacilli on Cattle. The 



inoculation of the pathologic products of tuberculous cattle or cultures 

 of bovine tubercle bacilli is usually followed by the development of 

 a severe tuberculous affection, w^hich frequently ends fatally within 

 4 to 8 weeks. Cases are observed, however, in which local lesions 

 only result. 



Thus Arloing was able, in some cases, to produce only local changes 

 at the point of inoculation or in the regional lymph glands by sub- 



