582 EXPERIMENT STATION EECOED. 



an attenuated virus were tried on immune pigs, but the results were unsatis- 

 factory. Somewhat better results for obtaining attenuated virus were given 

 by the simultaneous method. The animals were infected by way of the con- 

 junctiva with virus and were given immune serum intramuscularly. 



With the idea of preparing immune serum at lower cost the urinary filtrate 

 of cholera hogs was tried. The results with horses were negative, but in the 

 case of hogs antisera were obtained which were as potent as the ones produced 

 with virus serum filtrates. Uremic symptoms were noted in some of the ani- 

 mals treated with large amounts of urine filtrates. Organ extracts were also 

 tried. 



The lungs, liver, spleen, kidneys, lymphatic glands, mucosa of intestines, 

 and intestinal contents of all hogs coming to autopsy were given bacteriological 

 examination. The bacteria were studied in millc, litmus millf, Loffler's mala- 

 chite green, Barsiekow's solution I and II, Hetsch's solution, glucose and lactose 

 bouillon, and neutral red and orcein agar, and as regards their biological and 

 serological behavior. Out of 90 animals segregated in special cages only 14 

 showed the Bacillus suvpestifer, while 15 out of 20 pigs which were allowed 

 to run with other infected hogs showed it. The organisms at first did not 

 agglutinate with pestifer and paratyphoid B sera. It seems possible that 

 secondary bacteria present in hog cholera migrate into the blood stream of 

 affected animals. 



In addition to the paratyphoid group of bacteria, the bacteria of the 

 hemorrhagic septicemia group may also be present. The greatest percentage of 

 B. suipestifcr, B. enteritidis (Giirtner), and B. siiisepticus were found in the 

 stables where the animals were allowed to run together. The B. suisepticics 

 isolated was virulent for mice, guinea pigs, rabbits, and pigs. Variable results 

 were obtained with B. suipestifer and B. enteritidis (Gartner) with shoats. 

 In some cases the injection of B. suipestifer produced a disease similar to hog 

 cholera, especially the intestinal changes. B. suipestifer (Voldagsen), according 

 to Dammann and Stedefeder (E. S. R., 24, p. 390), and the Gliisser bacillus, 

 i. e., B. typhi suis, do not produce indol, nor is litmusmannite-nutrose solution 

 (Hetsch) affected. The organisms were pathogenic for pigs, but large doses 

 were necessary. The best route of infection was per os. Shoats rendered 

 immune against the filterable virus could only be infected (either by the 

 intravenous or os route) in a few instances. Spontaneous infection tests 

 showed that these bacteria are not in any way infectious, as one is led to 

 believe from the work of Pfeiler and Kohlstock (E. S. R., 32, p. 378) and 

 Weidlich (E. S. R., 32, p. 83). 



The bacteria isolated could be differentiated by culture studies and the 

 agglutination tests. Notwithstanding this, some Voldagsen cultures were found 

 labile in their behavior when examined culturally as well as serologically. In 

 some cases Voldagsen strains were influenced soon after isolation by para- 

 typhoid B and pestifer sera. 



The behavior of Gliisser bacteria with specific sera is also discussed. 



When to vaccinate ag'ainst hog cholera {California Sta. Circ. 132 (1915), 

 pp. Jf, fig. 1). — This circular gives advice concerning the early recognition of 

 hog cholera, the methods for immtinization, means of preventing the spread 

 of the disease, and an announcement of the sale of antihog-cholera serum by 

 the University of California. 



Some diseases of the respiratory tract of the horse which resemble glan- 

 ders, E. JoEST {Ztschr. Infektionskrank. u. Hyg. Haustiere, 16 (1915), No. 4, 

 pp. 239-263, figs. 10). — The pathological changes in the upper respiratory tract 

 dealt with include tuberculosis of the mucous membrane of the nares, cicatrices 

 of the nasal mucous membrane, tumor-forming amyloidosis of the nasal vesti- 



