CAUSATION OF DISEASE 309 



names of organisms he had found in the material from simi- 

 lar wounds, though he did not establish their causal rela- 

 tion. Bollinger, in 1872, discovered the spores of anthrax 

 and explained the persistence of the disease in certain dis- 

 tricts as due to the resistant spores. In 1873, Obermeier 

 observed in the blood of patients suffering from recurrent 

 fever long, flexible spiral organisms which have been named 

 Sjnrochceta obermeieri (more recently Borrelia recurrentis) . 

 Losch ascribed tropical dysentery to an ameba, named by him 

 Amoeba coli (now named Entamoeba histolytica), in 1875. 

 Finally, Koch, in 187G, isolated the anthrax bacillus, worked 

 out the life history of the organism and reproduced the dis- 

 ease by the injection of pure cultures and recovered the organ- 

 ism from the inoculated animals, thus establishing beyond 

 reasonable doubt its causal relationship to the disease. 

 This was the first instance of a bacterium proved to be the 

 cause of a disease in animals. Pasteur, working on the 

 disease at the same time, confirmed all of Koch's findings, 

 though his results were published the next year, 1877. 

 Bollinger determined that the Actinomyces bovis {Strepto- 

 thrix bovis) is the cause of actinomycosis in cattle in 1877. 

 Woronin in the same year discovered a protozoan {Plasmo- 

 diophora brassicoe) to be the cause of a disease in cabbage, 

 the first proved instance of a unicellular animal causing a 

 disease in a plant. In 1878, Koch published his researches 

 on wound infection in which he showed beyond question 

 that microorganisms are the cause of this condition, though 

 Pasteur in 1837 had suggested the same thing and Lister 

 had acted on the theory in preventing infection. 



Burrill.at the University of Illinois in the years 1878 to 1881 

 demonstrated the cause of "fire blight" of apple and pear 

 trees to be due to a bacterium, the first instance of a plant 

 disease proved to be due to a bacterium. 



These discoveries, especially those of Koch, immediately 

 attracted world-wide attention and stimulated a host of 

 workers, so that within the next ten years most of the bac- 

 teria which produce disease in men and animals were iso- 

 lated and described. It is well to remember that the first 

 specific disease of man proved to be caused by a bacterium 

 was tuberculosis by Koch in 1882. 



