PART I 

 NATURE'S DEFENSE 



CHAPTER LXXVIII 

 THE GREAT FACT 



FORTY-FOUR contagious and infectious diseases 

 attack Man. Forty-four species of Invisible Foes 

 are the active causes. 



In the fight, 30,000,000 human beings fall every 

 year. All the wars between man and man of a 

 hundred years do not begin to make such slaughter. 



Each foe is identified by its peculiar traits; yet 

 all the forty-four different kinds have traits in 

 common. 



They all are so small as to require a powerful 

 lens to reveal them to the naked eye. 



They all are transparent; only by the use of 

 staining dyes can they be seen at all even with 

 the powerful lens. 



They all take food in the same way by absorp- 

 tion through surface of body. 



They all digest their food before absorbing it. 



They all are mobile can move. 



They all propagate. 



They all multiply some wonderfully fast, one 

 becoming 16,500,000 in 24 hours. 



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