_Immunization_ is somewhat more promising than in hog cholera. Metchinkoff and Th. Smith working independently found a fair measure of success in inoculating rabbits and guinea pigs with three to five small injections of sterilized bouillon cultures, agar cultures or blood, intravenously, intraabdominally or hypodermically. But as applied to swine it has not proved satisfactory, and the irregularity of the results and the tendency to induce unthriftiness have caused it to be abandoned. _Treatment._ The therapeutics of swine plague like that of hog cholera is essentially unsatisfactory. Benefit might be derived in individual cases from a careful and judicious use of drugs to meet the special indications, but with the comparatively low value of the individual animal, the certainty of the multiplication of the deadly poison by the preservation of the diseased, and the extreme danger of its diffusion and extension, treatment is anything but commendable. _Serum-therapy_ has been advocated for years by De Schweinitz, and under the auspices of the Bureau of Animal Industry it has been given a wide trial, but it has not met with the full success that was at first claimed for it. The serum is prepared in a similar way to that of hog cholera and is similarly employed. It is open to the same class of objections, and though when skillfully employed it will reduce the mortality, it does not yet seem to have reached the point at which it can be recommended as a profitable investment. Like all temporizing measures it draws attention from the sounder and more economical measure of extinction and is indirectly a means of the perpetuation and even the diffusion of the infection. So long as extinction cannot be secured, this is a less valuable alternative for the adoption of owners of high priced hogs. MODIFIED AND COMPLEX FEVERS OF SWINE. Double infections. Varieties of bacillus choleræ suis, and bacillus suis pestis. McFadyean’s swine fever bacillus. Marseilles swine plague bacillus. We accept fully the duality of the Hog Cholera and Swine Plague, though this duality has been hotly contested on both sides of the Atlantic. Many of the best observers in Europe now support this position. These include Selander, Bang and Jensen who are familiar with the _svinpest_ (hog cholera) of Scandinavia; Kitt, Friedberger and Fröhner who are familiar with the _Schweineseuche_ (swine plague) of Germany; Raccugla, Canova and others in Southern Europe; and Lignieres and others in France who have studied the hog cholera and _pasturellose porcine_ (swine plague).