THE MODES OF ORIGIN 



OF 



LOWEST ORGANISMS. 



THE mode of origin of Bacteria, and, to a less extent, 

 of TorulcB, has been much discussed of late, and many 

 different views have been advocated on this subject by 

 successive writers. 



It is of much importance to bear in mind when such 

 views are under consideration, that a short time since 

 nothing was positively known concerning the life- 

 history of these organisms. However strongly, there- 

 fore, certain persons are inclined to rely upon the 

 analogy which is supposed to obtain between these 

 doubtful cases, and the multitudes of known cases 

 -in which it can be shown that organisms are the 

 offspring of pre-existing organisms it must always 

 be borne in mind that in many of the doubtful cases, 

 where the simplest organisms are concerned, there is 

 also an analogical argument of almost equal weight 

 adducible in favour of their de novo origination - 

 after a fashion, and under the influence of laws 



B 



