SPONTANEOUS GENERATION. 173 



to assign to them a spontaneous origin altogether incompati- 

 ble with what we know of organic development. Their 

 rapid appearance is not at all astonishing, when we reflect 

 that some mushrooms attain a considerable size in a few 

 hours, but yet pass through all the phases of regular growth ; 

 and, indeed, since we have ascertained the different modes of 

 generation among the lower animals, no substantial difficul- 

 ties to the axiom, " omne vivum ex ovo" (275,) any longer 



exist. 



15* 



