40 Microbes and You 



them microbes. We know today that typical anthrax bacteria are 

 non-motile, but movement was accepted as an important criterion 

 of microbes by many workers in those days. 



Being a man of modest means and unable to equip his labora- 

 tory with large numbers of animals for experimentation, Koch was 



r - * .- , * *"* * > A' H 







Fig. 13. Koch's photographs of anthrax bacilli. {From Fundamen- 

 tals of Bacteriology, M. Frobisher, 2nd. ed. Copyright 1942, W. B, 

 Saunders Company, Philadelphia.) 



obliged to conduct much of his early research under field condi- 

 tions. This added complications but it also added weight to his 

 final conclusions. Mice were available and were relatively cheap 

 to maintain, but he wasn't even sure that they were susceptible to 

 this disease. He proposed to inject some of the infected blood 

 containing these rod-shaped "things" into mice, but with no con- 



