BUREAU OF ANIMAL INDUSTRY. 



2G3 



111 tlie many cultivations which 1 have made from material obtained 

 from slaughtered animals I have never found bacilli except in a very 

 few cases where the virus was not obtained until after contact with the 

 air, where the vacuum tabes had not been properly sealed, or where 

 the animal was not slaughtered until the last stages of the disease. A 

 photograph of a preparation made from one of these cultivations is re- 

 produced in Plate XI. It seems to be a perfectly pure cultivation of 

 micrococci so far as careful examination with the microscope is able to 

 determine, and it was so virulent that three pigs inoculated with it all 

 contracted the disease and all died. 



In my most recent investigations I find that the peritoneal effusion 

 is often impure in the last stages of the disease. In such cases a vari- 

 ety of organisms appear in the cultivations mnd% with this liquid, but 

 pure cultures of micrococci are still obtained from the pleural effusion, 

 or in those rare cases where this too is impure the pericardial fluid and 

 blood have yielded pure cultures of micrococci. A fact of great im- 

 portance is that no pure cultures of bacilli have been obtained, and that 

 where but a sin ale species of organism has multiplied this has invaria- 

 bly been a micrococcus. 



Having obtained such results from my investigations, and having re- 

 peated them over and over again, and confirmed them with virus from 

 various parts of the country, I cannot but conclude that swine plague - 

 is due to a micrococcus, and that the disease produced by Dr. Klein's 

 cultivated bacilli was a form of Septicemia. And this conclusion is 

 confirmed by the short period of incubation in his cases, and the fact 

 that many of his animals showed no signs of disease other than a slight 

 rise of temperature and an enlargement and congestion of the lymph 

 glands. 



The following record of experiments contains the most important of 

 those which have been made since my last report, and is a continuation 

 of the evidence upon which the above statements have been made: 



Experiment No. 1. — Two pigs were inoculated June 28, 1883, witli 

 virus dried on quills and sent from Indiana. It was obtained by killing 

 a sick pig and immediately dipping the quills in peritoneal and pleural 

 effusion and the exudation liquid from the lungs, and drying this after 

 the manner practiced for preservation of vaccine lymph. In this case 

 the animal from which the virus was obtained di 1 not have a very 

 severe form of the disease. For inoculatiou the virus on three or four 

 quills was rubbed up with 2°°- of salt solution and injected under the 

 skin of thigh. The fourth day (July 2) there was elevated temperature 

 (102|° and 103 ] ° F.) and slight redness at the point of inoculation. The 

 fifth day there was diffused redness on the inner side of both thighs, 

 an eruption of small papulae on the thin parts of the skin and an in- 

 creased elevation of temperature (103f° and 104f° F.). July 5 to 9 

 the temperature remained at or al)ove'l05° with one, and reached its 

 highest point on the 7th, being then 105|°, and the eruption was very 

 plain and extended over the greater part of the surface of the body. 

 From this time they began to improve, and in neither case was the 

 disease fatal. 



This was one of a number of inoculation experiments made to obtain 

 a reliable virus for experimental purposes, and is recorded to illustrate 

 the above remarks in regard to the period of incubation. 



Experiment No. 2. — Four hogs were inoculated July 7, with virus 

 also from Indiana, and preserved in the same way as the other, but was 

 obtained from an outbreak which was much more virulent and fatal. 



