2O THE MYSTERY OF LIFE. 



not that very matter have been, and the very 

 forces manifested by it, have been for ages, 

 and might not similar conditions as regards 

 heat, light, moisture, and others, have per- 

 sisted, and for any length of time, and 

 yet no living stuff of any kind have been 

 evolved ? 



But those who teach that life is force will 

 not begin by demonstrating the facts they rely 

 upon in connection with simple living things, 

 and gradually advance from these to the con- 

 sideration of more complex beings. If we are 

 to learn anything about living things in general 

 surely our instructors should direct our attention 

 to the phenomena occurring in the lowest and 

 simplest beings, and during the earliest stage 

 of development of a complex creature, instead 

 of commencing upon a man, a full account of 

 whose life-phenomena cannot be comprised in 

 many volumes. 



Now, why do so many philosophers exhibit 

 little inclination to begin by inquiring about the 

 simplest living things ? Why do our text- 

 books begin with the consideration of the com- 

 plex physiology of the fully developed man, 

 instead of discussing, in the first place, the 



