22 Microbes and You 



representing the soul. Only after the soul enters the matter, does 

 life originate. He said in 354 B.C., "Animals sometimes arise in 

 soil, in plants or in other animals." 



Facts are established by repeated, confirmed observations. But 

 as stated in the introduction of this book, scientific facts remain 

 only until something proves them to be otherwise. The develop- 



Fig. 7. Francesco Redi (1626-1697). (From Elementary Bac- 

 teriology, /. E. Greaves and E. O. Greaves, 5th. ed. Copyright 1946, 

 W. B. Saunders Company, Philadelphia.) 



ment of newer knowledge may completely nullify previously 

 accepted facts. 



Some unusual recipes for creating living forms are inserted here 

 for your edification. They were based upon repeated observations 

 and were accepted at the time. Publius Vergil (70-19 B.C.) in 

 the Georgics suggested this technic for producing swarms of in- 

 sects: "First, a space of ground of small dimensions is chosen; this 

 they cover with the tiling of a narrow roof with confining walls, 

 and add four openings with a slanting light turned toward the 

 four points of the compass. Then a bullock, just arching his horns 

 upon his forehead of two years old, is sought out; whilst he 

 struggles fiercely, they close up both nostrils and his mouth; and 



