QH 



PREFACE 



DISCUSSION about the origin and devel- 

 opment of life upon this globe cannot 

 now be discountenanced nor prevented. 

 It is a subject too interesting and too im- 

 portant to be ignored by any intelligent 

 person. Being at present actually the 

 leading subject of scientific investigation, 

 the general reader should become ac- 

 quainted at least with the principles of 

 that investigation, enough to enable him 

 to avoid many prevalent misconceptions 

 about the conclusions so far reached. 



Previous to our own age, views on this 

 question were based either on speculation 

 or on tradition. They now claim to be 

 based entirely on observation. But ob- 



