786 EXPERIMENT STATION RECORD. 



'■ LMiiing the process of liyperimmiinizatiou. the agglutinin content of a pig's 

 serum increases as a rule as the amount injected increases, and may fall during 

 the tail bleedings unless more virus be injected. 



" If the agglutinogen in the virus is B. cholerw suis then the quantity 

 of agglutinogen (number of B. cholerw suls) injected into a large serum bog 

 during the whole process of hyperimmunization would ordinarily (if only 

 freshly drawn virus is used) be less than would be contained in 0.1 cc. of a 

 24-hour bouillon culture of B. cholerw suis. 



"The injection of a number of B. cholera- suis, in bouillon culture, equal to 

 that fouud in the total quantity of virus sufficient to hyperimmunize a large 

 pig fails to stimulate the production of agglutinin to such an extent as is the 

 case when the virus is injected. 



"Over one-third of the cases of serum hogs studied furnish a serum aggluti- 

 nating at a dilution of 1 : 50,000. 



" The Dorset-Niles serum retains its agglutinative power for several days, 

 almost unimpaired, when preserved in 0.5 per cent carbolic acid, trikresol, or 

 formalin. The agglutinative power of a serum may diminish 50 per cent, more 

 or less, after a period of 6 to 8 months. 



"The potency of the Dor set-IS' lies serum, the biological test being the stand- 

 ard, can not be measured uniformly by its agglutinative power for B. cholerw 

 suis. However, the biological test with pigs is a variable standard. 



" Serums of high agglutinative power, i. e., reacting at 1 : 2.000 or above, were 

 potent in 85.71 per cent of cases and not jwtent in 14.28 per cent : serums of 

 low agglutinative power, i. e., reacting at 1 : 1,000 or less, were potent in 45.45 

 per cent of cases and not potent in 54.54 per cent. 



"The agglutinability of the different cultures used by us indicates that they 

 belong to the same strain. They were isolated from the spleen of virus pigs 

 treated by virus having a common origin. We therefore believe that these cul- 

 tures originated in the original virus and not in an alleged normal habitat in 

 the pig's intestine. 



" |The author] believes that the relation of B. cholerw suis to the porcine 

 organism and to the filterable virus, and all the interrelation of these 3 fac- 

 tors in the prodiiction of a swine disease should be settled." For Instance, it 

 was found that " the protection offered by the Dorset-Niles serum against the 

 filterable virus may also extend to virulent cultures of B. cholerw suis. Whether 

 it is necessary to protect against B. cholerw suis in practice was not deter- 

 mined. The relation of B. cholerw suis to the filterable virus or to natural out- 

 breaks of hog cholera was not determined by this work or to the satisfaction 

 [of the author J by the researches of others." " A scientific understanding of 

 hog cholera is impossible without this solution. The economic problems involved 

 in the production of the Dorset-Niles serum or any other biological therapeutic 

 agent for hog cholera and the sanitary police control and eradication of this 

 disease demand it." 



Investigations of the pathological histology, pathogenesis, and post- 

 mortem diagnosis of contagious cerebro- spinal meningitis (Borna disease) 

 of the horse, E. Joest and K. Degen (Ztsehr. Infektionskrank. u. Hyg. Hau- 

 sticrc, 9 (.1011), No. 1-2, pp. 1-98, pis. 6; abs. iu Berlin. Tieriirztl. Wchnschr., 

 27 (1911), No. 25, pp. .',53, J,51t; Jour. Compar. Path, and Ther., 2/, {1911), 

 No. .'f, pp. 369, 370). — " The disease is an acute, diffuse, infilti-ative, nonpurulent, 

 meningo-encepha litis and myelitis of the lymphocyte type and chiefly meso- 

 dermal (vascular) in character. The albumin and chlorin contents of the 

 cerebro-spinal fluid of horses suffering from the disease do not differ from those 

 found in horses not suffering from diseases of the nervous system. 



