SPONTANEOUS GENERATION. 51 



of microbian life a world which has been aptly 

 described as " the world of the infinitely little." 



General Advance in Science. 



The general progress of science, however, points 

 towards some process of Evolution far more unmis- 

 takably than does anything disclosed during the 

 long controversy regarding spontaneous generation. 



Geology and physical geography have taught us 

 that our earth is subject to mutations and fluctua- 

 tions innumerable; paleontology has revealed a world 

 whose existence was not only not suspected, a few 

 generations ago, but a world whose existence would 

 have been unhesitatingly denied as contrary to both 

 science and Scripture, if anyone had been bold 

 enough to proclaim its reality. Far from being only 

 six thousand years old, as was so long imagined, our 

 globe, as the abode of life, must now, as is shown by 

 the study of the multifold extinct forms entombed 

 in its crust, reckon its age by millions, if not by tens 

 of millions of years. 



By the naturalists of the last century the num- 

 ber of known species of plants and animals was esti- 

 mated at a few thousands, or a few tens of thousands 

 at most. But now, owing to the impetus which has 

 been given to the study of zoology and botany, 

 especially during the past few decades, the latest 

 census of organic beings places the number of spe- 

 cies at a million or more. Yet formidable as this 

 number is, the list is far from being complete. Fresh 

 additions are being made to it every day. The re- 

 searches of naturalists in the many unexplored 



