308 BACTERIA PATHOGENIC TO MAN 



such quantities as are known never to produce reaction in healthy 

 individuals, would seem to afford the best protection against unpleasant 

 results and misleading evidence." 



Antituberculous Serum. Whether serum therapy is destined to solve 

 the problem of the treatment of tuberculosis remains for the future to 

 decide, but up to the present the results obtained with antituberculous 

 serum do not warrant our forming such an opinion. Every conceivable 

 way of obtaining the true products of the tubercle bacilli has been 

 tried, so as to cause the injected animals to produce antibodies both 

 antitoxic and bactericidal. At present Maragliano and Marmorek 

 are presenting claims that their sera are truly curative. Although 

 both these men have had a large experience in this field of investigation, 

 it is probable that the final judgment will be that little good comes 

 from the injection of their serum. Very few observers have succeeded 

 in obtaining appreciable results with the serums prepared by other 

 experimenters. In spite of much conflicting testimony, it is probably 

 safe to assert that no sera now obtainable have any great value. Nor 

 as we look at the progressive nature of tuberculosis can we see much 

 ground to hope for the abundant development of curative substances 

 in the blood of animals. This view, however, in no way lessens the 

 necessity of continued endeavor until every method conceivable has 

 ly^en tried. 



Prophylaxis. Meanwhile all energies should be directed to the pre- 

 vention of tuberculosis, not only by the enforcement of proper sanitary 

 regulations as regards the care of sputum, milk, meat, disinfection, etc., 

 but also by continued experimental work and by the establishment of 

 free consumptive hospitals, and by efforts to improve the character of 

 the food, dwellings, and condition of the people in general, we should 

 endeavor to build up the individual resistance to the disease. It may 

 be years yet before the public are sufficiently educated to co-operate 

 with the sanitary authorities in adopting the necessary hygienic meas- 

 ures to stamp out tuberculosis entirely; but, judging from the results 

 -which have already been obtained in reducing the mortality from this 

 dread disease, we have reason to believe that in time it can be com- 

 pletely controlled. 



The Tubercle Bacillus of Cattle and its Relation to Human Tuberculosis. 

 Among the domestic animals tuberculosis is most common in cattle. 

 On account of the milk which they provide for our use, and which is 

 liable to contain bacilli, the relation of these to human tuberculosis is 

 a matter of extreme importance. 



The chief seat of the lesions is apt to be the lungs, and with them the 

 pleura; less often the abdominal organs and the udder are affected. 

 In pigs and horses the abdominal organs are most often involved, then 

 the lungs and lymphatic glands. In sheep and goats tuberculosis is 

 rare. The bovine bacillus, as the most important of the group, will be 

 alone considered here. 



The bacilli derived from cattle are on the average a little shorter and 

 straighter than the average human bacillus. In guinea-pigs, and espe- 



