32 Veterinary Medicine. 



outbreak of two distinct varities of microorganisms, in place of 

 one, giving rise, of course, to modifications in the symptoms, 

 lesions, progress, mortality, etc. 



Apart from the microorganisms the whole class tends to show 

 a close family relationship in their pathological phenomena 

 shown under different conditions : 



ist. Under a large dose, or specially virulent germ, in a par- 

 ticularly susceptible animal, all tend to a manifestation of an 

 acute septicaemia, with generally diffused petechise of the skin,, 

 mucosae, serosse and internal organs, blood extravasations, and 

 an early high mortality. 



2d. Under a smaller dose, or a less potent germ, or in a less- 

 susceptible animal the tendency is to necrotic processes in the 

 seat of inoculation or the point of election of local lesions. Ne- 

 crotic ulcers are especially common in cases that survive one, twO' 

 or three weeks, or that develop in a subacute or chronic form. 



3d. With a minimum dose of a germ of little potency, and in a 

 very resistant subject even the necrotic lesions may be absent,, 

 and there may be suppuration only or ulceration of serosse and 

 joints. 



The question of the primary identity, or disparity of the whole 

 class of germs, causing the septicaemic swine plagues, may be 

 practically ignored in this work ; it is important rather with our 

 present knowledge to note the diseases associated with particular 

 germs, or varieties of germs, and to describe these as far as 

 possible as independent affections. This is as permissible as 

 it is to describe small-pox, sheep-pox, and cow-pox as distinct 

 affections, no matter what may be the truth or falsity as to their 

 alleged original identity. 



Rouget in Europe and Hog Cholera and Swine Plague, as the 

 best established types in the United States deserve primary men- 

 tion, to be followed by references to additional types which have 

 been found to be associated with other distinct microorganisms. 



