140 ANNUAL REPORT OF THE Off. Doc. 



quency of tuberculosis of the udder. Dilution with the milli of other 

 row? free from tuberculosis no doubt lessens the danger, but does not 

 i-(Mnove it. 



Acid-fad Bacdli. — A few 3'ears ago Moller amiounced the dis- 

 covery of a bacillus having the morphology and staiiiitJg reactions of 

 the tubercle bacillus. lie has shown that this bacillus and other:4 

 closely allied to it may constantly be found in forage and in the feces 

 uf aiiiuuils fed on such forage. Petri, Kabinowilsch, Grassberger, 

 Korn, and others have found the same or like bacilli in milk, butter, 

 and margariwe; Kabinovvitsch lias isolated one of the same group 

 from a case of gangrene of the lung in man; Karlinsky has shown 

 their presence in nasal mucus, and Marpman has found them io urine, 

 so that we know that this group of "acid-fast" bacilli has a wide dis- 

 tribution in Mature. The property of resisting decolorization by 

 mineral acids was for a long time considered diagnostic of the tuber- 

 cle I acillus. The discovery, therefore, of a comparatively large group 

 of organisms having the same property, and being indistinguishable 

 morphologically under the microscope, has served to throw some 

 doubt on researches in which the microscope has been relied on en- 

 tirely to demonstrate the presence of the tubercle bacillus in milk. 

 AniTx^als such as guinea-pigs and rabbits inoculated intraperitoneally 

 witu cultures of these bacilli, or with milk, butter, etc., containing 

 them, develop nodules which may sometimes be mistaken for tuber- 

 culosis. However, such mistakes must be rare, and there can be no 

 doubt that the true tubercle bacillus passes into the milk of tuber- 

 cular cows, as shown above. Reinoeulation, microscopic examina- 

 tit u of the tissues, and the isolation of cultures can be relied upon 

 to clear up the diagnosis of an}^ doubtful cases. 



Solution of the Problem. — In the solution of the problem before 

 I - the most directly valuable data will, I think, be obtained from the 

 examination of cultures isolated from the abdominal organs of chil- 

 dren in whom there is reasonable evidence of infection by the in- 

 testinal tract. When these cultures are found to have a high de- 

 gree of pathogenic power, and are able to infect cattle in moderate 

 dos'.'S, we will be justified in saying that the children from whom they 

 were obtained were infected in the first instance from bovine sources. 

 By the examination of a large number of such cases we will, I believe, 

 obtain very valuable information as to the frequency with which chil- 

 dren are infected by milk. On the other hand I do not consider 

 that we can entirely exclude bovine infection even iq those cases 

 where the abdominal organs yield a culture of feeble virulence, for 

 the reason that we at present know nothing of the effect produced 

 on the bovine bacillus by prolonged residence in the human body. It 

 is certain that the various types of tubercle bacillus known to us have 

 sprung from a stock common to them all, and that have acquired 



