306 THE BEGINNINGS OF IIFE. 



And whilst collateral evidence of all kinds points to the 

 conclusion that the presence of these Ciliated Infusoria 

 in various infusions is explicable only on the supposi- 

 tion that they have been derived from the *^ pellicles' 

 vi^hich form upon such infusions, every stage of their 

 heterogenetic origin may also be watched with the 

 greatest ease by the microscopist. 



Thus although evidence of the most varied and 

 conclusive nature concurs in attesting the frequency 

 with which processes of Archebiosis and Heterogenesis 

 occur, no facts are favourable to the mere assumptions 

 of the Panspermatists, whilst the hypothesis upon which 

 they rely is cumbersome, unwieldy, and now utterly 

 unnecessary. 



