Life is purely a physical phenomenon. 

 All the phenomena of life depend on 

 mechanical, physical, and chemical causes, 

 which are inherent in the nature of matter 

 itself. The simplest animals and the sim- 

 plest plants, which stand at the lowest 

 point in the scale of organization, have 

 originated and still originate by spon- 

 taneous generation, 



— Jean Lamarck, 1809. 



