1 8 ORIGIN OF LO WES T OR GA NISMS. 



3. ORIGIN OF BACTERIA AND OF TORUL/E BY 



ARCHEBIOSIS. 



The evidence on this part of the subject is, I think, 

 sharply defined and conclusive. Simple experiments 

 can be had recourse to, which are not admissible in 

 the discussion of the question as to the origin of Bac- 

 teria and Torulcz'by Heterogenesis. There, we wish to 

 establish the fact that living matter is capable of un- 

 dergoing a certain metamorphosis, and consequently, 

 we must deal with living matter. Here, however, with 

 the view of establishing the fact that living matter 

 can arise de novo, if we are able, shortly after beginning 

 our experiment, to arrive at a reasonable and well- 

 based assurance that no living thing exists in the her- 

 metically sealed experimental vessel if the measures 

 that we have adopted fully entitle us to believe that 

 all living things which may have pre-existed therein 

 have been killed we may feel pretty sure that any 

 living organisms which are subsequently found, when 

 the vessel is broken, must have originated from some 

 re-arrangements which had taken place amongst the 

 not-living constituents of the experimental solutions, 

 whereby life-initiating combinations had been formed. 



The possibility of the de novo origination of Bacteria, 

 Torulcz, and other such organisms, is one which is inti- 

 mately associated with the doctrine as to the cause of 

 fermentation and putrefaction. With regard to the 

 almost invariable association of such organisms with 



