CHAPTER XXIV. 



BACILLI OF TYPHOID COLON HOG CHOLERA GROUP BACILLUS 



CHOLERA SUIS BACILLUS TYPHOSUS BACILLUS COLI COM- 



MUNIS WHITE SCOURS IN CALVES MALIGNANT CATARRH 



OF CATTLE BACTERIUM PHLEGMASIA UBERIS 



BACILLUS TYPHI MURIUM DANYSZ'S BACILLUS 



PSITTACOSIS BACTERIUM PULLORUM. 



THERE is a rather large group of bacilli which have a number 

 .of common properties and the phylogenetic inter-relations of which 

 are evidently comparatively intimate. They do not resemble each 

 other as closely as the bacilli of the hemorrhagic septicemia group, 

 but sufficiently to warrant their classification under one group. All 

 are rather short, plump rods, they are generally motile, and possess 

 a varying number of flagella; they do not form spores, they lose the 

 stain if treated by Gram's method, they are facultative aerobics and 

 they do not liquefy gelatin. They differ in their biologic properties 

 as to their fermentative power toward various sugars (hexoses and 

 disaccharids), as to their ability to form gases, acids, indol, and a 

 number of other metabolic products, and especially as to their patho- 

 genicity toward man and the lower animals. The following organisms, 

 among others, belong to this group: The bacillus of hog cholera; the 

 Bacillus coli communis, or colon bacillus; the bacillus of mouse 

 typhoid; the bacillus of human typhoid and the paratyphoid bacillus; 

 the various dysentery bacilli; the Bacillus enteritidis; the Bacillus 

 fsecalis alkaligenes, etc. 



THE BACILLUS OF HOG CHOLERA. 



Occurrence and Historical. The bacillus of hog cholera, Bacillus 

 cholerse suis, or Bacillus suispestifer, was formerly believed to be the 

 sole cause of the acute and highly contagious disease of swine, known 

 variously as hog cholera, swine fever, pneumoenteritis, pig typhoid, 

 cholera suum; Schweinecholera, or Schweinepest (German), and Pest 

 du pore (French). While it has become evident that this disease in 

 its pure and uncomplicated form is due to a filterable ultramicro- 

 scopic virus and not to a bacillus, yet the latter often infects swine 

 during the course of hog cholera and is beyond doubt more or less 

 pathogenic for these animals. The earliest outbreak of hog cholera 

 was reported in Ohio in 1833, and since then the disease has spread 

 over the entire United States. It is believed that the epidemic was 



