138 PICTURING MIRACLES 



infected with bacteria and then ensued one of the 

 most moving and dramatic incidents of my micro- 

 scopic observations. I watched them multiply and 

 spread over all of the mold spores, killing them just 

 as one might imagine a fever spreading through a 

 human body. Spreading in a great cloud, it was an 

 excellent example of two forms of plant life, one 

 living on, and killing the other. When these spo- 

 rangia and zygospores form even a very tiny colony 

 they would be growing on a piece of bread no larger 

 than a pea, but ripened, they scatter enough spores 

 through the air to infect anything in that locality. 

 They are carried by the wind, and are in the dust 

 in every schoolroom. We are inhaling them con- 

 tinually, but as long as our bodies are kept healthy, 

 they do not affect us. 



