Tuberculosis in Man. 607 



tuberculous cows or after injuries acquired wlien making post- 

 mortem examinations of tuberculous animals. Even more 

 positive in this respect has been the evidence furnished by 

 the fact that tubercle bacilli, agreeing in their pathogenic 

 properties in every particular with those of the bovine type, 

 have been isolated from the lesions of tuberculous persons, 

 especially children (see p. 623). 



If, in spite of this, bovine tuberculosis plays only a 

 secondary role in the dissemination of tuberculosis in man 

 the cause for this, may in part at least, be found in the fact 

 that human beings do not live in as close association nor come 

 in as intimate contact with tuberculous cattle as they do with 

 their fellow beings. 



Puhnonary consumption, the commonest form of human tuber- 

 culosis, appears to be caused ahnost always by the human type of 

 the bacillus. Koch only recently emphasized the fact that up to that 

 time the bovine type of bacillus had not been demonstrated in a single 

 case of human pulmonary tuberculosis. Indeed Kitasato could find 

 only the human type of bacillus in 152 and Dieterlen in 50 examina- 

 tions of sputum from consumptives. But Mohler & Washburn as 

 well as Beitzke report each one case in M^hich they succeeded in ob- 

 taining pure cultures of the bovine type from such material. In 

 {general the bacilli of the bovine type seem to possess only a slight 

 tendency to spread in the human body, consequently they produce, 

 in the majority of cases, only local lesions in the region of the point 

 of infection (peripharyngeal, cervical and mesenteric glands). 



The danger which threatens man in the direction of bovine 

 infection demands the maintenance of every measure of pro- 

 tection by means of which this danger may be averted. 



In this respect all raw animal products, and particularly 

 milk, demand adequate consideration. There seems to be no 

 question as to the justification of the demand that all cows 

 with open tuberculosis and such as have affected udders be 

 unconditionally excluded from dairy purposes and that all milk 

 offered for sale to the public should be subject to professional 

 or expert supervision. Herds supplying creameries and skim- 

 ming stations should be subjected to particularly stringent 

 regulations for the reason that a single infected herd or animal 

 may be the means of contaminating the entire product of a 

 large station. Control of this character should confine itself 

 not merely to the exclusion of diseased animals but also to 

 enforcement of general sanitary regulations in the production 

 and handling of the milk, thus insuring the healthfulness of 

 the various other dairy products, butter, cheese, etc. 



Since suitable measures of control of this kind are at 

 present enforced in very few localities, it is incumbent upon 

 every individual to observe certain measures for his own pro- 

 tection. Uncertified milk should not be used as food without 

 previous boiling or at least heating to 80° C. Children, in 



