360 THE BEGINNINGS OF LIFE. 



Some exhibited rapid serpentine movements, accom- 

 panied by flexions of the two segments of which they 

 are composed ; whilst the movements of others were 

 rapidly progressive in straight or curved lines. 



The pellicle was made up mainly of simple Leptothrix 

 filaments (mostly without joints or evidences of seg- 

 mentation) ; and the thicker islets were found to be 

 produced by a more luxuriant growth in these situations 

 of densely interwoven filaments. 



The pellicle was found to be so tough and elastic 

 that some of it could only be mounted as a micro- 

 scopical specimen after it had been compressed for an 

 hour or two, by placing a small weight on the covering 

 glass. 



It would be useless to quote other experiments of 

 the same kind, though many others have been made with 

 similarly positive results. Those in which a hay infusion 

 acidified by carbolic acid has been employed are 

 most especially interesting. In no case has a properly 

 prepared infusion of turnip failed to yield an abundance 

 of living organisms in the course of from two to six 

 days, although the reaction of the infusion has always 

 been decidedly acid. A distinct pellicle, however, only 

 forms occasionally. If a clear solution becomes turbid 

 in a few days, with or without the formation of a thick 

 pellicle, and if on microscopical examination the cause 

 of the turbidity or the constituents of the pellicle have 

 been found to be Bacteria, Vlhriones, or Leptotkrix fila- 



