266 THE BEGINNINGS OF LIFE. 



amount of truth there is in the Panspermic hypothesis '. 

 Although the startling revelations made to us by the 

 microscope in this field of research are of such a nature 

 as scarcely to admit of any other interpretation than 

 that which we have given, still it is now desirable — 

 partly in regard to these investigations, and partly with 

 reference to subsequent enquiries — that we should know 

 what kinds of living things are to be met with in the 

 atmosphere, and whether or not they are abundantly 

 represented. 



In the first sentence of his ^Considerations sur les 

 Corps Organises/ the celebrated Charles Bonnet explains 

 the reasons which have been instrumental in bringing 

 about all the discussions concerning the existence 

 and distribution of ^ Germs.' He says that philosophy 

 being unable, in accordance with known laws, to ex- 

 plain the mode of formation of organized beings, ^ hap- 

 pily conjectured that they existed already in miniature, 

 under the form of Germs or Organic Corpuscles,' and 

 then goes on to state that this idea gave rise to two 

 hypotheses 2. He adds: <^La premiere suppose que les 

 Germes de tous les Corps organises d'un meme espece, 

 etoient renfermes, les uns dans les autres, et se sont 



^ It will, of course, now (after all the evidence we have adduced) be held 

 probable that most of the Bacteria of infusions are derived from others 

 which have been evolved de novo — even in solutions exposed to the air. 



2 Liebig says : — ' In the earliest period it was believed that metals 

 were developed from a seed or germ ; at a later period the opinion pre- 

 vailed, that the chemical process, generated the seed.' (' Letters on 

 Chemistry,' 3rd ed. p. 69.) 



