44 Microbes and You 



appear and turn into the original rod-shaped microbes so char- 

 acteristic of the ones in the anthrax-infected animals. Like a flash, 

 the truth of the situation occurred to him. Here was the answer to 

 the "cursed" pasture land; these beads were spores capable of 

 withstanding drying for extended periods of time, and the rigors 

 of winter could not kill them. Those pasture lands were con- 

 taminated with resistant forms of these bacteria, and when sheep 

 grazed on these fields, they ingested the spores and became in- 

 fected. Now he was ready in 1876 to announce to the world the 

 cause of anthrax. 



With self-assurance for the first time in many long, arduous 

 months, Koch determined to journey to Breslau to visit an old 

 friend who had encouraged him durino; his earlv ventures in re- 

 search. This friend was Professor Ferdinand Cohn, the first person 

 to work out a scheme for classifying bacteria in the plant kingdom. 

 He carried along some of his deadly anthrax organisms and some 

 of his mice on this particular trip, since he proposed to show 

 Professor Cohn the completeness of his findings with respect to the 

 deadly disease. Cohn invited anvbodv who was anvbody in the 

 scientific world to attend a lecture bv Koch in which he was to 

 present his research findings. Few had ever heard of this man 

 who had been working quietly without the aid of fancy laboratory 

 equipment, but many came to the presentation more out of 

 curiosity than faith in what Koch might have to say. Because 

 Koch was not an outstanding orator, he used the demonstration 

 technic of teaching in place of the lecture method, and he put 

 on a show that amazed the most learned scientists in the audience. 

 He gave his theories and then proved his beliefs with actual animal 

 experimentation. The renowned Professor Julius Cohnheim ( 1839- 

 1884), who first demonstrated that pus was composed largely of 

 white blood cells, and who was without doubt the leading authority 

 on disease in Europe, was most impressed with the clarity and 

 conclusiveness of Koch's presentation. Koch had converted a 

 disciple! Because of Cohnheim's influence, Koch was compelled 

 to turn away scholars who came in droves to study under his 

 tutelage. When he announced to members of his class, including 



