THE BEGINNINGS OF LIFE. 427 



these changes all early botanical and zoological dis- 

 tinctions seemed to vanish. Our notions of species,, 

 genera, families,, orders, and even other more general 

 classificatory distinctions, appeared to be swept away, 

 one by one, in the face of the successive modifications 

 and metamorphoses which these simple organisms were 

 capable of undergoing. 



