CHAPTER II. 

 THE ORIGIN OF LIFE. 



The early philosophers of all nations referred human 

 existence directly to our parents and indirectly to the 

 gods, although it seemed to them a simple matter that 

 the lower forms of life should come into being de novo. 

 Belief in the spontaneous generation of the lower forms 

 of life accentuated as philosophy slowly separated itself 

 from religion. Greek philosophy is replete with expres- 

 sions regarding the spontaneous generation of the lower 

 forms of life, and the idea persisted through the middle 

 ages to become a matter of paramount interest during 

 the latter half of the nineteenth century. 



The most superficial consideration of the subject is 

 sufficient to show that among the ancients it .was un- 

 f amiliarity with the lowly forms of life that led to such a 

 notion, but more modern writers seem to have been 

 led astray through the expansion of knowledge following 

 the invention of the microscope which introduced them 

 to a world of newer and simpler forms of life, and thus 

 changed the problem. Thus, one possessed of the most 

 elementary information upon natural history might 

 scout the idea that such complexly organized beings 

 as mice could be spontaneously generated, though the 

 same difficulties might not at first stand in the way of 

 conceiving that amoeba or bacteria might be. 



As the conception of spontaneous generation has 

 undergone modifications consistent with the evolution 

 of knowledge in general, it is worth while to review the 

 subject and see what it has meant, and what it now 

 means to those who, in spite of all the evidence at hand, 

 continue to adhere to it. 



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