ORIGIN OF LO WES T OR GA NISMS. 1 1 



Heterogenesis ; although, as I have just stated, in 

 respect to such low and changeable organisms, 

 scarcely any distinct line of demarcation can be drawn 

 between Homogenesis and Heterogenesis. 



The evidence seems, therefore, against the notion 

 that Bacteria or Torulce are ordinary, independent 

 living things, which merely reproduce their like. 



That some Bacteria are produced from pre-existing 

 Bacteria, just as some Tornlce are derived from pre- 

 existing Tornlce, may, it is true, be considered as 

 settled. But, so far as we have yet considered the 

 subject, there may be just as good evidence to show 

 that Bacteria and Tor nice are capable of arising de 

 novo, as there is that some of them are capable of 

 developing into fungi. 



If this were the case, such types could only be 

 regarded as the most common forms assumed by 

 new-born specks of living matter ; and, by reason of 

 their orisrin which would entail an absence of all 



o 



hereditary predisposition they might be supposed to 

 be capable of assuming higher developmental forms. 



Now, as a matter of fact, worthy of arresting our 

 attention, we do find that some Bacteria are capable of 

 growing into Leptothrix, whilst this is able to develop 

 continuously into a fungus ; just as we also know 

 that some Tor nice are capable of growing into other 

 fungi. 



Should it be established, therefore, that Bacteria 

 and Tornlce are capable of arising dc novo, the facts 



