Safeguards against Disease 151 



stories in the relationship of bacteria to man 

 if we could only wander back along the ways 

 of evolution. For we have all grown up 

 together through the ages, we and the bacteria, 

 each adapting himself to the requirements 

 of the other. When this mutual adjustment 

 is secured, we do each other no harm. Our 

 cells and the bacterial cells then work hand in 

 hand. Infectious diseases are the efforts of 

 adaptation to conditions which have not yet 

 become usual. That the invading micro- 

 organisms in infection also have their hour 

 of storm and stress, as they encounter the 

 damaging forces which our cells command, 

 is proven every time we get well. 



Bacteria, as we have seen, make trouble 

 in the body very little by their mere physical 

 presence, but by poisons which some of them 

 form and set free as they live and grow, or 

 which they store up to be liberated when they 

 die and break to pieces. So when in our 

 cherished interiors the poison-breeding bac- 

 terial cell encounters our well bred body cell, 

 it is a battle in which the weapons are poisons. 

 For some of the fluids and digestive juices 



OF THE 

 IIMIVFRSITY 



