364 THE BEGINNINGS OF LIFE. 



partially preserved. The reaction of the fluid was found 

 to remain slightly acid. 



On microscopical examination of the sediment, Bac- 

 teria were found, having moderately active movements 

 though they were not very numerous. There were 

 many granular aggregrations, from the midst of which 

 were growing Leptotkrix filaments, though the organisms 



_ 



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Fio. 25. 



Torulce, Leptothrix, and Bacteria found in simple Solution of 

 Ferric and Ammonic Citrate. ( x 800.) 



which were most abundant wereToru/a cells of different 

 sizes, many of which were provided with a segment 

 across their short diameter, whilst each half contained 

 a nuclear particle. These Torula cells had a uniform 

 very faint greenish hue, and homogeneous contents. 

 They often existed in groups of 1 2-20, or more. 



Experiment 2. A closed flask containing a solution of 

 ferric and ammonic citrate, together with a few minute 

 fibres of deal wood (much less than half a grain), was 

 opened 42 days after it had been hermetically scaled. 



The fluid continued clear and there was no pellicle on 

 the surface, though, after the first two weeks a slight 



