1 882.] A Pathogenic Schizophyie of. the Hog. 297 



outside. If, however, the possibility of a spontaneous generation 

 is not admitted, the Schizophytes cannot be produced, or be 

 called into existence by the morbid process. 



As evidence that the swine-plague Schizophytes constitute the 

 true cause of the morbid process, and the infectious principle of 

 the disease, by which the latter is communicated from animal to 

 animal, from herd to herd, and from one locality to another, I can 

 offer the following facts, which may not constitute absolute proof, 

 but, if considered in toto, make it reasonably certain that the Schizo- 

 phytes, and nothing else, constitute the cause and the infectious 

 principle of the disease. 



1. Every inoculation of healthy pigs which never had become 

 infected with swine-plague, when made with material contain- 

 ing swine-plague Schizophytes — lung-exudation for instance — 

 proved to be effective, and produced the disease in due time, be- 

 tween three and fifteen days, or on an average in five to six days, 

 notwithstanding the very small quantity, usually not exceeding 

 the fourth part of one drop, with which the animal was inocula- 

 ted on the outer surface of the ear, provided no measures of pre- 

 vention were applied. For particulars I have to refer to my pub- 

 lished reports. Further, even an inoculation with filtrated lung- 

 exudation, in which no visible solid bodies whatever, except 

 Swine-plague micrococci, could be discovered, proved to be effec- 

 tive, and produced a mild form of the disease, while filtrated 

 lung-exudation, destitute of micrococci, when used to inoculate 

 a healthy animal, proved to be ineffective, and did not even cause 

 a visible reaction. 



2. Inoculations with swine-plague Schizophytes cultivated in 

 an innocent fluid, such as fresh cow-milk, albumen of a hen's 

 egg, etc., invariably produced the disease, though usually in a 

 comparatively mild form ; a fact which corresponds with the results 

 of the experiments, made by Toussaint, Pasteur, and Buchner 

 with Bacillus anthracis, and by Pasteur with chicken-cholera 

 microbes, and shows that the malignancy of pathogenic Schyzo- 

 phytes depends largely upon the nature of this pabulum. 



3- Swine, which survive an attack of swine-plague and recover, 

 possess afterwards either perfect, or what is more frequent, partial 

 immunity from further infection. In other words, subsequent in- 

 oculations, or a subsequent exposure to the influence of the in- 

 fectious principle, have either no effect whatever, or have only a 



